3?     PUM 


DOMESTIC  SCIENCE 

TEXT  BOOK 


Bakiflll     der 


A 

HEALTHFUL 

CONVENIENT 

LEAVENING  AGENT 


By 
THOMAS  G.  ATKINSON,  B.  Sc.,  M.  D. 


GIFT  OF 
E,  W.  Peixotto 


ira  R  Peixofto 

APR   11    1»19 


BAKING  POWDER 


A  Healthful 

Convenient,  Leavening 

Agent 


By 

THOMAS  G.  ATKINSON,  B.Sc.  (Lond.),  M.D.,  L.R.C.P. 

(Lond.) 

Professor  of  Physiology,  Jenner  Medical  College,  Chicago, 

Illinois;     Formerly     Professor     of     Physiology     and 

Physiological     Chemistry,    Chicago    College    of 

Medicine  and  Surgery,  and  in  the  American 

Medical   College,   St.    Louis,   Missouri. 

Staff  Editor  American  Journal  of 

Clinical  Medicine. 


THE  COMMONWEALTH  PRESS 
Publishers  of  School  Books 

CHICAGO,  ILLINOIS 


COPYRIGHT  1915 
THOMAS  G.  ATKINSON,  B.  Sc.,  M.  D. 


TABLE  OF  CONTENTS 


Pages 

CHAPTER  I.     Introduction 1-2 

Leavening  Agents.  Disadvantages  of  Yeast.  Advantages  of 
Baking  Powders.  Sources  of  Carbon  Dioxid. 

CHAPTER  II.    The  Ingredients  of  Baking  Powder'  3-13 

Soda.  Ammonium  Carbonate.  Magnesium  Carbonate. 
Other  Substances  Necessary.  The  Acid  Substance.  Tartaric 
Acid  and  Cream  of  Tartar.  Acid  Phosphate.  "Alum." 
Starch.  White  of  Eggs. 

CHAPTER  III.    Choice  of  an  "Acid"  Ingredient .  .  14-26 

Apparent  Difference  in  Baking  Powders.  Chemical  Action. 
Amount  of  Gas  Set  Free.  The  Amount  of  the  Residues.  The 
Healthfulness  of  the  Residues.  Keeping  Qualities.  Speed  of 
Action.  Properly  Balanced  Action. 

CHAPTER  IV.    The  Manufacture  and  Use  of  Bak- 
ing Powder 27-33 

Manufacturing  Appliances.  The  Use  of  Baking  Powder. 
How  to  Measure.  Care  of  Baking  Powder.  Self-Rising 
Flour. 

CHAPTER    V.     The  Determination  of  Available 
.  .    Carbon  Dioxid   35-39 

Harrison's  Method.     Absorption  Method. 

CHAPTER  VI.     Conclusion 40-41 

Cost  of  Baking  Powder.     Baking  Powder  a  Necessity. 

Questions >  ,  ,  .  42-45 

Answers 46-51 

Appendix    52-58 

Photographic  reproduction  of  Bulletin  No.  103,  United  States 
Department  of  Agriculture,  Contribution  from  the  Referee 
Board  of  Consulting  Scientific  Experts.  Ira  Remsen, 
Chairman. 


887343 


Domestic  Science  tfext  Book 


CHAPTER  I 

LEAVENING  AGENTS 

THE  common  leavening  agents  in  use  in  the  home 
are  yeast  and  baking  powder.  Yeast  is  a 
microscopic  plant  which,  in  the  leavening  process, 
produces  changes  which  finally  result  in  the  breaking 
up  of  sugars  into  alcohol  and  carbon  dioxid  gas. 
Baking  Powder  is  a  mixture  of  several  substances 
which  produce  this  same  gas  by  chemical  action.  This 
gas,  by  forming  in  small  bubbles  throughout  the  dough 
mass,  lightens  or  leavens  it.  Carbon  dioxid  gas  is 
sometimes  called  carbonic  acid  gas.  This  is  the  gas 
which  is  present  in  all  carbonated  waters,  whether 
natural  or  artificial,  as  in  soda  fountain  waters. 

DISADVANTAGES  OF  YEAST 

IN  the  case  of  yeast,  the  fermentation  which  produces 
the  gas  is  never  of  a  single  kind,  as  many  different 
fermentations  are  going  on  at  the  same  time.  It  is 
impossible,  commercially,  to  control  these  different 
fermentations  so  that  they  will  always  exist  in  the  same 
proportions  ;  hence,  we  find  that  the  flavors  from  differ- 
ent bakings  vary  greatly  and  are  sometimes  objection- 
able. Moreover,  several  hours  must  be  allowed  for  the 
process  of  fermentation  before  the  food  can  be  placed 
in  the  oven.  Fermentation  does  not  take  place  readily 
in  the  presence  of  large  quantities  of  butter,  lard  or 
eggs. 


Page  2  Domestic  Science  'Text  Book 

ADVANTAGES  OF  BAKING  POWDER 

WITH  a  properly  compounded  baking  powder, 
on  the  other  hand,  the  chemical  reaction  will 
always  be  the  same,  and  any  influence  which  it  may 
exert  upon  the  flavors  of  the  finished  food  will  always 
be  the  same.  Baking  powder  has,  moreover,  these  two 
further  advantages  over  yeast:  The  gas  is  given  off  at 
once  upon  the  addition  of  water  or  in  the  oven  during  the 
heating;  there  is  no  waiting.  And  the  presence  of  but- 
ter, lard  or  eggs  does  not  hinder  the  chemical  action. 

The  leavening,  from  whichever  source,  is  always 
the  result  of  the  same  gas,  carbon  dioxid,  and  in  the 
study  of  baking  powder  we  are  interested  in  learning 
how  this  gas  is  produced  by  chemical  action. 

SOURCES  OF  CARBON  DIOXID 

ARBON  dioxid  is  found  in  nature  combined 
chemically  with  many  metals,  and  these  combina- 
tions are  known  as  salts  of  carbonic  acid,  or  more 
commonly  as  carbonates.  Those  with  which  one  is 
most  familiar  are  chalk,  marble  and  limestone,  all  of 
which  are  different  forms  of  calcium  carbonate.  If 
any  of  these  are  heated  to  a  very  high  temperature, 
carbon  dioxid  gas  is  set  free  and  lime  remains;  but 
this  very  high  temperature  is  never  reached  in  baking. 
Baking  soda  is  another  carbonate  with  which  all  are 
familiar. 


Domestic  Science  Text  Book  Page  3 

CHAPTER  II 

THE  INGREDIENTS  OF  BAKING  POWDER 

SODA 

SODA  is  the  carbonate  which  is  used  at  home  for 
cooking  purposes;  it  is  also  commonly  known  as 
saleratus,  or  baking  soda.  This  is  the  carbonate  used 
almost  exclusively  in  the  manufacture  of  baking  pow- 
der and  always  named  on  the  label  as  soda.  It  is  some- 
times referred  to  as  the  alkali  of  the  baking  powder. 
It  is  a  white  crystalline  substance  of  very  high  purity, 
being  as  free  from  impurities  as  the  granulated  sugar 
used  at  the  table.  It  is  manufactured  from  common 
salt  through  the  action  af  acid  ammonium  carbonate. 

The  reaction  is  represented  by  the  following  equa- 
tion: 

NaCl  +  NH4  HC03  =  NaH  CO3  +  NH4  Cl 
Salt     Acid  Ammonium          Soda          Ammonium 
Carbonate  Chloride 

Soda,  when  heated,  readily  gives  off  carbon  dioxid 
gas,  and  hence  may  be,  and  often  is,  used  in  cooking 
without  the  addition  of  any  other  substance  for  the 
purpose  of  leavening.  The  heat,  however,  does  not 
drive  off  all  of  the  gas.  The  reaction  which  takes  place 
is  represented  by  the  following  formula : 

2NaHCO3    =    Na2CO3    +    H2O    +    CO2 
Soda  Normal  Sodium     Water      Carbon 

Carbonate  Dioxid 


Page  4  Domestic  Science  T^ext  Book 

The  residue  of.  normal  sodium  carbonate  thus  left 
in  the  bread  gives  it  a  disagreeable,  alkaline  taste,  and 
also  colors  the  bread  an  objectionable  yellow;  hence, 
soda  by  itself  is  unsatisfactory  for  use  as  a  leavening 
agent. 


AMMONIUM  CARBONATE 

AMMONIUM  carbonate  has  been  sometimes  used 
as  a  leavening  agent.  This,  upon  being  heated, 
breaks  up  into  two  different  gases,  ammonia  gas  and 
carbon  dioxid  gas.  Some  of  the  ammonia  gas  remains 
in  the  bread  when  cooked;  therefore,  its  use  in  baking 
powder  has  been  almost  entirely  discontinued. 


MAGNESIUM  CARBONATE 

MAGNESIUM  carbonate  is  the  only  other  sub- 
stance at  present  used  for  the  purpose  of  furn- 
ishing carbon  dioxid  gas.  The  heat  of  the  oven  is  not 
sufficient  in  this  case  to  cause  all  the  gas  to  be  set  free. 
Magnesium  carbonate  is  a  very  light  powder.  One 
pound  will  occupy  as  much  space  as  six  pounds  of 
soda.  The  purpose  of  those  who  use  this  ingredient  in 
the  manufacture  of  baking  powder  is  mainly  to  add  to 
the  bulk  of  the  powder  and  thus  make  the  thoughtless 
purchaser  believe  she  is  getting  more  for  her  money. 


Domestic  Science  tfext  Book Page  5 

OTHER  SUBSTANCES  NECESSARY 

IT  will  be  seen  from  what  has  just  been  said,  that 
none  of  these  carbonates  are,  of  themselves  alone, 
satisfactory  for  baking  purposes.     Something  else  is" 
necessary. 

If  one  has  ever  dropped  a  little  vinegar  on  some 
soda,  he  has  noticed  that  a  gas  was  set  free.  This  is 
carbon  dioxid  gas.  Vinegar  contains  an  acid,  acetic 
acid,  and  it  is  the  action  of  this  acid  upon  the  soda  that 
sets  free  the  gas.  Any  soluble  acid  will  have  this  same 
action  on  soda,  hence,  if  we  unite  such  an  acid  with 
the  carbonate,  soda,  we  have  the  necessary  substances 
with  which  to  produce  carbon  dioxid  gas. 


THE  ACID  SUBSTANCE 

FOR  the  making  of  baking  powder,  both  acid  and 
carbonate,  however,  must  be  dry  substances,  and 
not  liquid,  as  acetic  acid  or  vinegar  is.  The  acid  should 
also  dissolve  in  water.  There  are  many  such  dry  acids, 
most  of  them  organic  substances.  Citric  acid,  the  prin- 
cipal acid  contained  in  lemons,  is  one  of  these.  Tar- 
taric  acid  is  another. 

Beside  the  true  acids,  there  are  some  salts  which 
have  an  acid  nature  and  which  are  called  acid  salts. 
Of  these,  calcium  acid  phosphate,  commonly  called  acid 
phosphate,  is  one,  and  potassium  acid  tartrate,  com- 


Domestic  Science  ^ext  Book 


monly  known  as  cream  of  tartar,  is  another.  There 
are  some  salts  which  are  not  acid  salts  (inasmuch  as 
all  of  the  hydrogen  atoms  of  the  acid  have  been  re- 
placed by  a  metal)  which  nevertheless  act  as  very  weak 
acids.  The  most  common  of  these  is  sodivim  aluminum 
sulphate,  sometimes  called  "Alum. 


" 


Any  of  these  three  kinds  of  substances,  the  acid,  the 
acid  salt,  or  the  salt  with  acid  properties,  acts  upon  soda 
and  sets  free  carbon  dioxid  gas.  The  action  takes  place 
almost  as  quickly  as  the  "acid"  or  salt  dissolves.  These 
substances  just  mentioned,  acid  phosphate,  "alum," 
tartaric  acid  and  cream  of  tartar,  together  with  the 
soda,  are  the  active  principles  in  baking  powder.  In 
addition  to  these  there  is  generally  a  quantity  of  starch 
and  sometimes  dried  white  of  egg.  Soda  has  been  stud- 
ied. The  other  substances  must  now  be  considered. 


TARTARIC  ACID  AND  CREAM  OF  TARTAR 

r  1 1 ARTARIC  acid  is  manufactured  from  Argol, 
A  which  is  the  sediment  that  separates  out  at  the 
bottom  of  the  wine  vat  during  the  fermentation.  This 
substance  is  colored  by  the  color  from  the  grapes,  and 
is  a  mixture  of  tartaric  acid,  calcium  tartrate,  cream  of 
tartar  and  all  kinds  of  organic  impurities.  This  mix- 
ture is  dissolved  in  water,  precipitated  with  powdered 
chalk  and  calcium  chloride,  filtered  and  then  the  pre- 
cipitated calcium  tartrate  is  dissolved  in  sulphuric  acid. 


Domestic  Science  Text  Book  Page  7 

This  solution  is  again  filtered  and  treated  with  some 
decolorizing  agent,  such  as  hone  black  or  infusorial 
earth,  and  the  subsequent  clear,  colorless  solution  evap- 
orated and  the  tartaric  acid  allowed  to  crystallize. 
Cream  of  tartar  is  also  obtained  from  the  same  sedi- 
ment, Argol.  It  is  decolorized  by  heating  with  animal 
charcoal  filtered  and  recrystallized. 

ACID  PHOSPHATE 

ALCIUM  Acid  Phosphate  is  prepared  from  the 
same  source  as  is  much  of  the  "Phosphate,"  used 
at  soda  fountains.  The  bones  from  healthy  cattle  are 
heated  in  large  revolving  cylinders  until  they  are  thor- 
oughly charred.  In  this  condition  the  mass  is  black 
and  is  known  as  bone  black,  although  in  reality  it  con- 
sists of  both  calcium  phosphate  and  charcoal.  This 
substance  is  used  to  decolorize  the  juices  of  the  cane  in 
the  manufacture  of  cane  sugar.  In  the  manufacture 
of  phosphate  it  is  again  heated  to  a  very  high  tempera- 
ture whereby  all  charcoal  is  burned  off  and  only  the 
calcium  phosphate  remains.  This  is  then  dissolved  in 
dilute  sulphuric  acid  and  the  calcium  acid  phosphate 
thereby  obtained,  purified  by  filtration.  It  is  then  fur- 
ther purified,  concentrated,  crystallized,  and  dried  to  a 
white  powder. 

A  more  recent  process  is  the  manufacture  of  phos- 
phate for  food  purposes  from  phosphate  rock.     This 


Page  8  Domestic  Science  tfext  Book 

material  was  not  formerly  used  on  account  of  the  great 
difficulty  of  excluding  from  the  finished  acid  phosphate 
the  harmful  impurities,  fluorides,  always  found  in  the 
rock.  Bone  phosphate  is  the  better  on  this  account  and 
is  always  used  by  the  careful  manufacturer  of  high- 
grade  baking  powder. 

Calcium  acid  phosphate  for  baking  powder  is  pre- 
pared in  two  degrees  of  fineness,  powdered  and  granu- 
lar. The  granular*  is  much  more  expensive  but  has 
the  great  advantage  of  making  a  baking  powder  that 
will  keep  longer  than  one  made  from  powdered  phos- 
phate. 

"ALUM" 

THE  so-called  "Alum"  used  in  baking  powder  is 
not  the  alum  which  is  sold  at  the  drug  store  by 
that  name.  The  common  alum  of  trade,  which  is  also 
used  as  medicine,  contains  potassium,  an  element  that 
is  toxic  in  very  small  quantities,  and  water  of  crystal- 
lization; it  is,  in  fact,  potassium  aluminum  sulphate, 
combined  with  water  of  crystallization,  K  Al  (SO4)2 
12(H2O).  The  so-called  "alum"  of  baking  powder 
is  a  different  thing  and  is  more  properly  named 
sodium  aluminum  sulphate,  being  a  mixture  of  sodium 
sulphate  and  aluminum  sulphate,  both  of  them  harm- 


*The  acid  phosphate  as  found  in  Calumet  Baking  Powder  is 
of  the  granular  type. 


"Domestic  Science  tfext  Book  Page  9 

less  and  non-toxic.  It  contains  neither  potassium  nor 
water  of  crystallization.  The  term  alum  has  been 
used  for  this  article  on  baking  powder  labels  at  the 
request  of  some  food  commissioners  who  felt  that  this 
word  would  be  better  understood  by  the  common  people 
as  showing  in  a  general  way  the  character  of  the  sub- 
stance. Unfortunately,  it  has  largely  had  the  very  dif- 
ferent effect  of  misleading  the  public  into  the  erroneous 
idea  that  it  actually  is  the  alum  of  commerce  and  of 
medicine — a  mistake  of  which  certain  manufacturers 
have  not  failed  to  take  advantage  in  decrying  baking 
powders  containing  alum. 

It  is  prepared  by  mixing  solutions  of  the  two  sul- 
phates, sodium  sulphate  and  aluminum  sulphate,  con- 
centrating the  mixture  and  fusing  the  resulting  dried 
mass.  This  leaves  a  mixture  which  for  our  present  pur- 
poses we  may  designate  by  the  formula: 

Na  Al  (SO4)2 

Sodium  Aluminum  Sulphate 

There  is  no  potassium  in  this  substance  at  all,  as  there 
is  in  the  common  alum,  and  no  ammonia  as  in  the  less 
common  ammonium  alum. 


Page  10  Domestic  Science  ^fext  Book 

STARCH 

WE  also  find  that  besides  the  soda  and  "acid," 
starch  is  used  in  baking  powder.     This  starch 
is  corn  starch  of  the  highest  grade  of  purity  and  spe- 
cially prepared  for  food  purposes. 

The  starch  serves  three  purposes,  two  of  which  play 
an  important  part  in  keeping  the  baking  powder  from 
spoiling,  while  the  third  adds  to  the  efficiency  of  its 
use. 

First:  It  separates  the  soda  from  the  acid  or  acid 
acting  salt  and  thus  by  mechanically  separating  them 
retards  such  chemical  action  as  could  be  brought  about 
by  moisture.  The  air  is  never  dry.  It  always  contains 
moisture.  This  is  very  noticeable  on  rainy  days,  but 
it  escapes  attention  in  fair  weather.  Not  only  is  carbon 
dioxid  set  free  when  water  or  milk  is  poured  on  the 
baking  powder,  but  even  the  moisture  in  the  air  gradu- 
ally causes  the  change.  Moisture  from  any  source  thus 
spoils  the  powder. 

Second:  Starch  absorbs  water  and  thus  prevents 
moisture  from  bringing  the  active  ingredients  in  con- 
tact with  each  other.  In  this  way  it  aids  materially 
in  keeping  the  powder  from  spoiling.  Starch  is,  for 
these  reasons,  a  necessary  ingredient  of  baking  powders, 
and  most  especially  necessary  in  the  case  of  straight 
phosphate  powders,  which,  even  when  starch  is  present, 
deteriorate  very  rapidly. 


Domestic  Science  Text  Book  Page  n 

Third'.  Starch  also  dilutes  the  strength  of  the  bak- 
ing powder,  so  that  it  may  be  made  to  produce  the 
amount  of  gas  desired  for  efficiency  and  for  conven- 
ience in  household  methods  of  measurement. 

The  laws  of  a  few  States  require  that  a  baking  pow- 
der shall  produce  at  least  10%  of  its  weight  of  carbon 
dioxid  gas.  Almost  all  baking  powders  are  made 
stronger  than  this.  The  majority  of  those  upon  the 
market  yield  12%  of  gas,  while  the  best  produce  be- 
tween 14%  and  15%. 

WHITE  OF  EGGS* 

F INHERE  is  one  ingredient  mentioned  above,  as 
JL  being  sometimes  used  in  baking  powder,  which 
has  not  yet  been  discussed.  That  is  Dried  White  of 
Eggs,  sometimes  called  egg  albumen.  It  is  prepared 
by  drying  the  white  of  fresh  hens'  eggs  at  a  low  tem- 
perature, and  then  grinding  to  a  fine  powder.  Fourteen 
pounds  of  whole  eggs  will  produce  about  one  pound  of 
this  dry  powder.  It  dissolves  easily  in  cold  water  and 
the  viscous,  egg-white  nature  of  this  solution  holds  the 
bubbles  of  gas  as  they  are  set  free  from  the  baking 
powder.  White  of  eggs  is  used  by  many  manufac- 
turers of  baking  powder.  This  increases  the  efficiency 
of  the  carbon  dioxid  gas  evolved  by  a  baking  powder  to 
an  extent  of  2.5%  to  3.2%  when  used  in  strong  baking 

*Calumet  and  Crescent  Baking  Powders  are  the  two  most 
widely  known  that  contain  white  of  eggs.  It  is  used  in  about  thirty 
different  brands  of  baking  powder. 


Page  12  Domestic  Science  T^ext  Book 

powders.  It  is  extremely  beneficial  in  producing  light 
biscuits  when  the  oven  temperatures  are  not  properly 
controlled  or  when  the  dough  has  to  stand  for  some 
time  before  baking. 

The  amount  of  dried  white  of  eggs  used  in  baking 
powders  is  very  small,  being  15/100  of  1%.  Even  in 
this  small  proportion  it  has  the  effect  above  mentioned. 
It  also  makes  possible  a  simple  test  whereby  the  fresh- 
ness of  baking  powder  may  be  determined,  by  the  sales- 
man in  testing  the  stock  upon  the  retailers'  shelves,  by 
the  grocer  himself,  or  by  the  housewife  in  the  home. 
Both  the  increase  in  lightness  and  the  possibility  of  the 
test  are  due  to  the  viscous  nature  of  the  white  of  eggs, 
whereby  the  bubbles  of  gas  are  imprisoned  as  soon  as 
they  are  set  free  by  chemical  action.  This  test  is  de- 
scribed by  one  manufacturer  as  follows: 

"First  take  an  ordinary  drinking  glass  holding  one 
half  pint,  or  in  other  words,  the  quantity  that  is  usually 
known  in  the  household  as  "one  cupful."  All  that  is 
needed  is  this  empty  glass,  which  must  be  dry,  an  ordi- 
nary teaspoon  and  a  little  water  of  the  ordinary  room 
temperature  (not  ice  water  nor  hot  water.)  Place  2 
level  teaspoonsful  of  the  powder  in  the  dry  glass,  to 
which  add  the  same  quantity  (2  teaspoonsful)  of  water 
quickly;  stir  rapidly  for  a  moment  (while  counting 
five),  just  long  enough  to  thoroughly  moisten  the  pow- 
der; remove  the  spoon  and  watch  the  mixture  rise. 
Note  the  action  of  the  powder.  It  rises  slowly  and 


Domestic  Science  tfext  Book  Page  is 

evenly,  requiring  2  minutes  to  show  the  full  strength. 
If  the  powder  is  of  full  strength,  and  you  have  pro- 
ceeded properly,  the  gas  released  will  form  bubbles  suf- 
ficient to  half  fill  the  glass. 

"Caution: — Don't  attempt  to  make  the  mixture  rise  by  continued 
stirring,  as  whipping  or  beating  the  mixture  breaks  the  gas  bubbles 
that  are  formed  and  allows  the  gas  to  escape.  Allow  the  powder 
to  rise  of  its  own  strength.". 

Manufacturers  make  the  following  use  of  this  test. 
Whenever  complaints  are  made  to  the  grocer  or  when 
goods  appear  to  have  been  stored  in  damp  places,  or 
too  near  the  stove,  the  salesman  tests  the  baking  pow- 
der as  above  described  and  if  it  is  found  to  have  deterior- 
ated, it  is  at  once  exchanged  for  fresh  goods  without 
cost  to  the  retailer.*  Without  this  simple  test  it  would 
be  necessary  to  send  the  goods  complained  of  to  the 
factory  for  chemical  analysis.  As  a  result  of  such  tests 
by  the  salesmen,  deteriorated  goods  may  be  entirely 
removed  from  the  market  so  that  the  consumer  will 
never  receive  a  baking  powder  which  does  not  do  its 
work  perfectly.  Of  course,  the  above  test  cannot  be 
made  unless  the  white  of  eggs  is  present. 


*The  Calumet  Baking  Powder  Company,  more  than  any  other 
company,  uses  this  method  in  testing  its  goods  on  the  grocer's  shelf 
to  keep  its  powder  in  perfect  condition. 


Page  14  Domestic  Science  tfext  Book 


i 


CHAPTER  III 
CHOICE  OF  AN  "ACID"  INGREDIENT 

T  has  been  seen  that  there  are  several  different  sub- 
stances available  to  set  the  carbon  dioxid  gas  free 
from  the  soda,  but  the  question  arises,  "How  shall  one 
decide  which  is  best  for  that  purpose?" 

APPARENT  DIFFERENCE  IN  BAKING 
POWDERS 

r  1 1  HE  principal  difference  between  different  baking 
A  powders  is  in  the  "acid"  used,  some  containing 
one,  some  another  and  some  a  combination  of  two  of 
these  "acids."  This  difference  is  apparent  to  anyone 
reading  the  labels.  All  the  ingredients  are  named  there. 

The  first  things  to  consider  are: 

( 1 )  Which  is  the  most  healthful  ? 

(2)  Which  will  set  free  the  most  gas? 

(3)  Which  will  make  a  powder  that  will  keep  best? 

(4)  And,  which  gives  off  its  gas  at  a  speed  best 
adapted  for  cooking  purposes? 

The  study  of  the  first  two  of  these  questions  involves 
a  knowledge  of  chemical  action  that  takes  place  be- 
tween each  of  the  "Acids"  and  the  soda.  From  the 
chemical  equation  we  can  determine  just  how  much  of 


Domestic  Science  tfext  Book 


Page  is 


the  "acid"  ingredient  is  necessary  to  set  free  all  the 
gas  from  the  soda  and  also  just  how  much  gas  is  set 
free,  and  just  how  much  soluble  residue  is  left  from  the 
reaction. 


CHEMICAL  ACTION 

THE  following  equations  show  the  formulas  of  the 
"acids"  and  soda,  and  of  the  substances  produced 
by  the  chemical  reaction.  Underneath  each  formula  is 
the  name  of  the  substance.  Underneath  each  name  is 
the  number  of  parts  by  weight  that  react  or  result  from 
the  chemical  reaction.  Underneath  these  is  given  the 
per  cent  of  soluble  residue  and  the  per  cent  of  carbon 
dioxid  gas  produced. 


H2C4H406  - 

h  2NaHCO3 

=  Na2C4H406  - 

f  2C02  - 

Tartaric 

Soda 

Sodium 

Carbon 

Acid 

Tartrate 

Dioxid 

150 

168 

194 

88 

61% 

27.7% 

2H2O 
Water 


36 


KHC4H4O 

Cream  of 

Tartar 

188 


NaHCO3  =  KNa  C4H4O6 
Soda  Rochelle  Salts 


84 


210 

77.2% 


CO 


H2O 


Carbon     Water 
Dioxid 

44  18 

16.2% 


Page  16 


Domestic  Science 


Book 


3CaH4(PO4)2  + 

8NaHC( 

>3  =  Ca3(P04)2 

+  4Na2HPO4 

+  8CO2 

Calcium  Acid 

Soda 

Calcium 

DiSodium 

Carbon 

Phosphate 

Phosphate 

Phosphate 

Dioxid 

702 

672 

310 

568 

352 

41.3% 

25.6% 

+ 

8H2O   (Water), 

144. 

2NaAl(SO4)2 
"Alum" 

484 


6NaHCO3  =  2Al(OH)3 
Soda  Aluminum 

Hydrate 
504  156 


4Na2SO4 
Sodium 
Sulphate 
568 

57.5% 


6CO2 
Carbon 
Dioxid 
264 
26.7% 


The  amount  of  "acid"  and  soda  given  in  each  case 
show  the  proportions  by  weight  in  which  they  should 
be  mixed  to  make  the  best  baking  powder.  If  more 
"acid"  is  used  just  that  much  "acid"  would  be  left  in 
the  food  unchanged.  If  more  soda  were  used,  just 
that  amount  would  be  unacted  on  by  the  "acid"  and 
would  leave  the  food  alkaline  and  yellow. 

Put  in  words,  the  above  equations  represent  the  chem- 
ical action  as  follows: 

One  hundred  and  fifty  parts  by  weight  of  tartaric 
acid  act  upon  168  parts  by  weight  of  soda.  Both  com- 
pounds are  completely  changed  and  there  is  formed  194 
parts  of  sodium  tartrate,  88  parts  of  carbon  dioxid  gas 
and  36  parts  of  water.  The  weight  of  the  sodium  tar- 
trate is  61%  of  the  sum  of  the  weights  of  tartaric  acid 
and  soda,  and  the  carbon  dioxid  is  27.7%. 


Domestic  Science  ^(ext  Book  Page  i? 

One  hundred  and  eighty-eight  parts  of  cream  of  tar- 
tar act  upon  84  parts  of  soda.  Both  compounds  are 
completely  changed  and  there  is  formed  210  parts  of 
Rochelle  Salts,  44  parts  of  carbon  dioxid  gas  and  18 
parts  of  water.  The  weight  of  the  Rochelle  Salts 
formed  is  77.2%  of  the  sum  of  the  weight  of  cream  of 
tartar  and  soda,  and  the  weight  of  the  carbon  dioxid 
gas  is  16.2%. 

Seven  hundred  and  two  parts  by  weight  of  acid  phos- 
phate act  upon  672  parts  of  soda.  Both  compounds 
are  completely  changed  and  there  is  formed  310  parts 
of  insoluble  calcium  phosphate,  568  parts  of  sodium 
phosphate,  352  parts  of  carbon  dioxid  gas  and  144 
parts  of  water.  The  weight  of  the  soluble  sodium  phos- 
phate is  41.3%  of  the  sum  of  the  weights  of  the  acid 
phosphate  and  soda,  and  the  carbon  dioxid  gas  is  25.6%. 

Four  hundred  and  eighty-four  parts  by  weight  of 
"alum"  act  upon  504  parts  by  weight  of  soda.  Both 
compounds  are  completely  changed.  There  is  no  "alum" 
and  no  soda  left.  There  is  formed  156  parts  of  insoluble 
aluminum  hydrate,  568  parts  of  sodium  sulphate  and 
264  parts  of  carbon  dioxid  gas.  The  weight  of  sodium 
sulphate  is  57.5%  of  the  weight  of  "alum"  and  soda 
and  the  carbon  dioxid  gas  is  26.7%. 

The  above  chemical  actions  show  what  takes  place 
between  the  "acid"  substance  and  the  soda.  The  per- 
centages given  show  how  much  soluble  residue  would 
be  left  and  how  much  gas  produced  if  a  baking  powder 
were  made  without  adding  any  other  substance. 


Page  is  Domestic  Science  "Text  Book 

AMOUNT  OF  GAS  SET  FREE 

THE  different  "acids"  with  soda  set  free  the  fol- 
lowing amounts  of  gas : 

Tartaric  acid 27.7% 

"Alum".    26.7% 

Acid  phosphate 25.6% 

Cream  of  tartar 16.2% 

Each  one  produces  more  gas  than  is  desired  for  ordi- 
nary household  purposes  and  methods  of  measurement. 
In  fact,  another  substance,- starch,  is  added,  which  plays 
no  part  in  the  production  of  gas  but  in  the  presence 
of  which  the  same  weight  of  the  mixture  produces  less 
gas  than  before.  Enough  starch  is  generally  added  to 
reduce  the  gas  strength  of  the  powder  to  between  12% 
and  15%.  The  amount  of  gas  that  can  be  produced 
by  an  "acid"  acting  on  soda  gives  us  no  information 
as  to  the  strength  of  a  baking  powder  containing  that 
"acid,"  for  the  reason  that  starch  is  always  added,  and 
in  different  proportions  by  every  manufacturer.  (There 
is  one  baking  powder  sold  in  the  dry,  mountain  States 
that  contains  no  starch.) 

THE  AMOUNT  OF  THE  RESIDUES 
r  I^HE  per  cent  of  soluble  residue  shown  in  the  pre- 
A     ceding  equations  by  the  different  "acids"  acting 
on  soda,  are  as  follows: 

"Acid"  Soluble  Residue 

Acid  phosphate 41.3%  Sodium  acid  phosphate 

"Alum"     57.5%  Sodium  sulphate 

Tartaric    acid 61.0%  Sodium  tartrate 

Cream  of  tartar 77.2%  Rochelle  salts 


Domestic  Science  tfext  Book  Page  19 

Inasmuch  as  the  powders  always  contain  added 
starch*  and  are  reduced  in  gas  strength,  a  fairer  com- 
parison of  the  amount  of  the  different  residues  may  be 
obtained  if  one  compares  the  amounts  of  soluble  resi- 
due left  from  the  different  kinds  of  powders  of  the 
same  gas  strength.  The  following  table  shows  the 
number  of  parts  by  weight  of  soluble  residue  produced 
by  100  parts  of  a  baking  powder  that  would  produce 
12%  of  gas. 

Kind  of  Powder  Residue 

Acid  phosphateft 19.4  parts  Sodium  acid  phosphate 

"Alum"**     25.8  parts  Sodium  sulphate 

Tartaric  acid 26.4  parts  Sodium  tartrate 

Cream  of  tartarf 57.2  parts  Rochelle  salts 

This  shows  that  Cream  of  Tartar  powders,  or  the 
mixture  of  Cream  of  Tartar  and  Soda  used  in  many 
households,  leaves  more  than  twice  as  much  objection- 
able residue  as  any  other  kind  of  baking  powder  for 
the  same  amount  of  leavening. 

THE  HEALTHFULNESS  OF  THE 
RESIDUES 

THE  healthfulness  of  these  substances  is  discussed 
in  Bulletin  No.  103  of  the  United  States  Depart- 
ment of  Agriculture,  professional  paper,  entitled  "Alum 


^Shillings'  is  a  baking-  powder  that  does  not  contain  starch. 

**Bon  Bon  and  Good  Luck  are  types  of  baking  powder  con- 
taining only  "alum"  as  an  acid  ingredient. 

fThe  principal  powders  leaving  Rochelle  salts  in  the  food  are 
Cleveland,  Royal,  Price's  and  Shillings'. 

tfRumford  baking  powder  is  the  most  prominent  of  this  class. 


Page  20  Domestic  Science  'Text  Book 

in  Foods,"  this  being  the  decision  of  the  Referee  Board 
after  a  long  extended  investigation.  The  members  of 
this  board  were  selected  by  the  President  of  the  United 
States  because  their  high  scientific  knowledge,  the 
eminent  positions  they  occupy,  and  the  complete  facil- 
ities for  investigation  at  their  command,  were  such  as 
to  render  their  conclusions  respect-impelling  and 
final.  The  following  are  a  few  quotations  from  the 
report: 

"Alum,  as  such,  is  not  present  in  the  food  when 
eaten." 

"There  is  no  evidence  in  our  results  to  indicate  that 
the  occasional  and  ordinary  use  of  bread,  biscuits,  or 
cake  prepared  with  aluminum  baking  powder  tends  to 
injure  the  digestion.  The  amount  of  saline  cathartic 
that  would  be  ingested  under  conditions  of  normal  diet 
would  be  very  small  and  would  provoke  no  catharsis 
or  symptoms  of  any  kind." 

"In  short,  the  board  conclude  that  alum  baking 
powders  are  no  more  harmful  than  any  other  baking 
powders." 

"We  must  not,  however,  be  oblivious  to  the  fact," 
says  Dr.  Taylor,  who  conducted  part  of  these  investiga- 
tions, "that  a  saline  cathartic  residue  results  from  the 
reaction  of  every  form  of  known  baking  powder  now 
commonly  employed.  The  use  of  cream  of  tartar  or 
tartaric  acid  baking  powder  leaves  in  the  alimentary 
tract  a  residue  of  tartrates  which  exhibit  the  action  of 


Domestic  Science  tfext  Book  Page  21 

a  saline  cathartic  and  of  diuresis  (excessive  excretion 
of  urine)  as  well.  The  so-called  phosphate  baking 
powder  leaves  as  a  residue  of  reaction  sodium 
phosphate,  again  a  saline  cathartic.  And  aluminum 
baking  powder  leaves  as  a  residue  of  reaction  sodium 
sulphate,  a  saline  cathartic.  Apparently,  therefore,  at 
present  at  least,  the  use  of  baking  powder  is  associated 
with  the  introduction  into  the  alimentary  tract  of  a 
certain  amount  of  saline  cathartic,  the  salt  differing 

with  the  use  of  the  particular  type  of  baking  powder." 

i 

This  last  paragraph  from  the  report  shows  the  char- 
acter of  the  residues  from  the  different  kinds  of  powder 
to  be  as  follows: 

Kind  of  Powder  Character  of  Residue 

"Alum" Cathartic 

Phosphate     Cathartic 

f  Cathartic 
Cream  of  tartar <        and 

[  Diuretic 

If  one  uses  9  grams  of  a  12%  baking  powder  to  a 
pint  of  flour  and  makes  therefrom  8  biscuits,  then  the 
number  of  such  biscuits  that  it  would  be  necessary  to 
eat  to  take  in  the  food  enough  of  the  residue  from  dif- 
ferent powders  to  equal  the  minimum  dose  as  given  in 
the  U.  S.  Dispensatory  is  shown  by  the  following  table: 

Dose  in  Grams  Kind  of  Powder  No.  Biscuits 

31.1  Phosphate                                         142 

15.5  "Alum"                                                53 

17.7  Cream  of  tartar                                28 


Page  22  Domestic  Science  tfext  Book 

From  the  above  facts  it  will  readily  be  seen  that 
there  is  no  basis  in  fact  for  the  continual  advertise- 
ment by  the  manufacturers  of  cream  of  tartar  baking 
powder  that  alum  baking  powders  are  injurious,  and 
that  the  cry  against  "alum"  is  merely  an  unjustified 
appeal  to  the  desire  for  health  in  order  to  sell  their 
own  baking  powder,  which  produces  not  only  cartharsis 
but  diuresis  as  well. 

It  is  this  latter  effect  which  is  most  worthy  of  re- 
mark and  study,  for  it  indicates  (what  is,  indeed,  the 
fact)  that  the  tartrates  are  absorbed  into  the  blood  and 
excreted  through  the  kidneys,  while  sodium  sulphate 
exercises  what  slight  action  it  has  upon  the  intestinal 
tract  alone. 

The  quantity  of  residue  in  either  case  is  so  small, 
as  shown  by  the  above  table,  that  its  eff ect  upon  the 
body  is  probably  inconsiderable  and  in  this  respect  alone 
the  "alum"  powder  would  have  the  advantage,  even 
if  the  residue  were  identical,  since  its  residue,  having 
regard  to  its  dosage,  is  only  about  one-half  that  of  the 
tartar  powder. 

But  in  quality  the  difference  is  still  more  marked. 
Recent  experiments*  have  shown  that  tartrates,  in 
larger  quantities,  have  an  injurious  effect  upon  the 
kidneys,  often  causing  nephritis.  Whether  small,  con- 
tinued doses  have  a  proportionately  mischievous  effect, 
is  still  a  matter  for  investigation.  Certainly  no  such 
action  has  been  ascribed  to  the  non-toxic  sodium  sul- 


Domestic  Science  T^ext  Book  Page  23 

phate.  Whatever  question,  therefore,  may  yet  remain 
as  to  the  healthfulness  of  the  respective  residues  is 
plainly  in  favor  of  the  "alum"  product. 


*  Journal  American  Medical  Association,  Vol.  LXII,  No.  8,  Feb. 
21,  1914,  p.  616.  Underbill,  F.  P.:  The  Influence  of  Tartrates  on 
Phlorhizin  Diabetes,  Proc.  Soc.  Exper.  Biol.  and  Med.,  1912,  IX, 
123;  The  Influence  of  Sodium  Tartrate  on  the  Elimination  of 
Certain  Urinary  Constituents  During  Phlorhizin  Diabetes,  Jour. 
Biol.  Chem.,  1912,  XII,  115.  Underbill,  F.  P.;  Wells,  H.  G.,  and 
Goldschmidt,  S. :  Tartrate  Nephritis,  with  Especial  Reference  to 
Some  of  the  Conditions  Under  Which  It  May  Be  Produced,  Jour. 
Exper.  Med.,  1913,  XVIII,  322.  Salant,  W.,  and  Smith,  C.  S.: 
The  Toxicity  of  Sodium  Tartrate,  with  Special  Reference  to  Diet 
and  Tolerance,  Proc.  Soc.  Exper.  Biol.  and  Med.,  1913,  X,  170. 
Pearce,  R.  M.,  and  Ringer,  A.  I.:  A  Study  of  Experimental 
Nephritis  Caused  by  the  Salts  of  Tartaric  Acid,  Jour.  Med.  Re- 
search, 1913,  XXIX,  57. 

Added  Potassium  Salts  in  Food,  A.  Cressy,  Morrison,  N.  Y. 


KEEPING  QUALITIES. 

A  TTENTION  has  already  been  called  to  the  fact 
£**  that  the  chemical  action  which  sets  free  the  car- 
bon dioxid  gas  and  which  should  take  place  only  in 
the  dough,  is  in  fact  brought  about  to  some  extent  by 
the  moisture  of  the  air.  We  have  also  seen  that  the 
starch  present  aided  in  two  different  ways  in  retarding 
such  action.  The  "acid"  used  is  also  a  very  important 
element  effecting  the  keeping  qualities  of  a  baking 
powder.  Baking  Powders  in  which  acid  phosphate  is 
the  only  "acid"  ingredient,  spoil  most  rapidly.  There 
is  a  comparatively  small  amount  of  this  kind  of  baking 


Page  24  Domestic  Science  tfext  Book 

powder  on  the  market  because  of  this  fact.  The  house- 
wife cannot  depend  on  the  goods  being  of  proper 
strength  when  the  goods  are  purchased.  When  pur- 
chased in  the  best  condition,  they  are  liable  to  deteriorate 
to  an  inefficient  mass,  even  in  the  home,  before  the 
contents  of  the  can  are  entirely  used.  Deterioration  of 
any  baking  powder  is  often  marked  by  caking  or  the 
formation  of  lumps.  Cream  of  Tartar  Baking  Powder 
has  good  keeping  qualities,  but  the  powders  containing 
"alum"  keep  best  of  all. 

SPEED  OF  ACTION 

THE  total  amount  of  gas  from  a  baking  powder 
may  be  produced  either  immediately  on  the  addi- 
tion of  cold  water,  or  only  after  a  long  time  and  after 
application  of  heat.  This  is  because  the  "acid"  dis- 
solves more  quickly  or  more  slowly  in  water.  The 
amount  of  gas  that  is  given  off  quickly  before  the  mix 
is  placed  in  the  oven  can  be  shown  in  the  following 
manner : 

Three  level  teaspoonsful  of  baking  powder  are  placed 
in  a  glass,  a  little  white  of  egg  added,  and  three  tea- 
spoonsful  of  water  added.  The  whole  is  then  immedi- 
ately stirred  until  all  of  the  baking  powder  is  moistened. 
If  this  is  done  with  the  "alum"  baking  powder  it  will 
be  found  that  very  little  gas  is  given  off.  A  powder 
in  which  phosphate  is  the  only  "acid"  ingredient  acts 
very  quickly  as  does  also  one  containing  tartaric  acid 
or  cream  of  tartar.  The  speed  of  action  or  the  amount 


Domestic  Science  tfext  Book  Page  25 

of  gas  thus  given  off  is  very  important  with  reference 
to  the  handling  of  the  baking. 

A  baking  powder  that  gives  off  nearly  all  of  its  gas 
in  the  cold,  as  does  a  straight  phosphate  or  a  tartaric 
acid  and  a  cream  of  tartar  baking  powder  will  produce 
a  large  dough  biscuit  before  being  placed  in  the  oven. 
The  dough  in  this  case  is  already  much  distended  and 
the  gluten  of  the  flour  will  not  hold  much  more  gas 
without  breaking  and  allowing  the  gas  to  escape.  Prac- 
tically all  of  the  gas  has  been  set  free  before  it  is  placed 
in  the  oven.  If  placed  in  an  oven  of  a  low  temperature, 
any  jarring  of  the  floor  or  slamming  of  the  door  of 
the  oven  is  likely  to  cause  a  fallen  cake.  This  danger 
applies  especially  to  straight  phosphate  and  to  cream 
of  tartar  and  tartaric  acid  powders. 

NOTE. — Most  of  the  widely  advertised  "pure  cream 
of  tartar"  baking  powders  contain  tartaric  acid.* 

On  the  other  hand  a  biscuit  prepared  from  a  straight 
"alum"  powder  which  gives  off  almost  none  of  its  gas 
in  the  cold,  would  produce  a  flat  dough  biscuit,  which, 
if  placed  in  the  oven,  would  have  very  little  surface 
upon  which  the  heat  could  act  to  penetrate  the  soggy 
mass  and  cause  the  powder  to  set  its  gas  free.  As  a 
result,  if  placed  in  a  very  hot  oven,  the  high  tempera- 


*Cleveland,  Royal  and  Price  Baking  Powders  contain  tartaric 
acid.     Shillings'  is  a  straight  cream  of  tartar  powder. 


Page  26  Domestic  Science  "Text  Book 

ture  would  crust  the  outside  of  the  biscuit  before  the 
gas  had  been  liberated,  thus  resulting  in  small,  heavy, 
poorly  leavened  biscuits. 

PROPERLY  BALANCED  ACTION 

A  STUDY  of  the  keeping  qualities  and  of  the  speed 
of  action  has  resulted  in  the  production  of  baking 
powders  containing  a  combination  of  two  of  these 
"acids."  The  most  notable  are  those  containing  phos- 
phate and  "alum."  The  aim  has  been  to  produce  a 
baking  powder  with  a  correctly  balanced  action,  giving 
off  a  proper  amount  of  gas  in  the  cold,  with  a  sufficiently 
large  amount  of  gas  that  will  only  be  given  off  on 
heating  the  mix  in  the  oven,  and,  at  the  same  time,  a 
powder  that  will  not  easily  spoil.  As  a  result  of  such 
consideration  and  extensive  experiments,  baking  pow- 
ders have  been  produced  superior  to  any  made  with  a 
single  "acid"  ingredient.  Properly  proportioned  pow- 
ders, of  the  "phosphate-alum"  type,  are  not  only  the 
best  in  keeping  quality,  but,  when  they  contain  sufficient 
phosphate,*  have  also  the  best  balanced  speed  of  action, 
and  insure  the  housewife  against  the  dangers  either  of 
fallen  biscuits  on  the  one  hand  or  of  biscuits  which 
have  crusted  over  too  quickly  to  obtain  the  desired 
lightness,  on  the  other  hand. 

*Calujnet  Baking  Powder  is  the  principal  powder  of  this  type. 


Domestic  Science  tfext  Book  rage  2? 

CHAPTER  IV 

THE  MANUFACTURE  AND  USE  OF 
BAKING  POWDER 

THE  manufacture  of  the  different  ingredients  nec- 
essary to  make  a  good  baking  powder  has  now 
been  considered.  The  manufacture  of  baking  powder 
itself  begins  with  the  ingredients  as  they  are  received 
from  the  different  manufacturers.  There  is  a  general 
impression  that  the  manufacture  of  baking  powder  con- 
sists of  merely  weighing  out  and  mixing  the  different 
ingredients.  This  opinion  is  shared  by  most  of  the  small, 
and  even  by  some  of  the  large  manufacturers.  It  is, 
however,  far  from  the  truth. 

The  manufacture  of  baking  powder  requires  the 
greatest  care  and  most  thorough  chemical  supervision. 
A  perfect  baking  powder  cannqt  be  made  by  one  who 
relies  upon  the  manufacturer  of  the  ingredients  to 
always  furnish  him  goods  of  the  same  purity,  the  same 
dryness,  or  the  same  strength. 

In  the  study  of  chemical  action  it  was  seen  that  where 
a  certain  weight  of  soda  was  used,  a  fixed  amount  of 
the  acid  ingredient  was  necessary  to  set  free  all  the 
gas.  If  more  acid  were  used,  just  that  much  acid  would 
be  left  unchanged  in  the  finished  food.  If-  less  acid 
were  used,  then  to  that  extent  there  would  remain  soda 
(or  sodium  carbonate,  an  alkaline  residue),  rendering 
the  food  yellow  and  disagreeable  to  the  taste.  The 


Page  28  Domestic  Science  T^ext  Book 

excess  of  acid  is  especially  undesirable  on  account  of 
the  physiological  effect  of  such  soluble  substances. 
Accordingly,  the  first  work  of  a  manufacturer  of  baking 
powder  is  to  test  the  ingredients  he  purchases  and  de- 
termine their  strength.  For  this  a  well-equipped  lab- 
oratory is  essential.  The  weights  of  the  ingredients 
are  then  adjusted  so  that  the  reaction  will  be  complete 
and  so  that  the  product  turned  out  today  will  be  the 
same  as  that  turned  out  yesterday,  neither  more  acid  nor 
more  alkaline.  Only  by  knowing  the  exact  strength 
of  the  different  ingredients  can  the  mix  be  thus  perfectly 
proportioned. 

It  is  because  these  quantitative  relations  between 
the  amount  of  soda  and  the  amount  of  acid  substances 
used  must  exist  for  the  production  of  a  proper  and 
perfect  baking  powder,  that  the  custom  of  mixing  soda 
and  Cream  of  Tartar 'still  used  in  many  homes  is  so 
objectionable.  It  is  safe  to  say  that  the  proper  pro- 
portions are  never  obtained  in  the  home  except  by  acci- 
dent, and  not  more  than  once  in  a  thousand  times.  A 
good  baking  powder  is,  therefore,  from  this  considera- 
tion alone,  much  to  be  preferred  to  such  a  mixture.  It 
is  also  customary  in  some  homes  to  use  soda  and  sour 
milk  in  place  of  baking  powder.  Here  again  the  proper 
proportion  is  impossible.  In  general,  too  much  soda 
is  used,  as  the  milk  ordinarily  contains  insufficient  sour- 
ness (lactic  acid)  to  set  free  all  the  carbon  dioxid  gas 
from  the  soda. 


Domestic  Science  T^ext  Book  Page  20 

Besides  the  analysis  for  strength,  the  manufacturer 
must  take  every  precaution,  by  analyses,  to  determine 
that  the  ingredients  are  of  proper  dryness.  This  is 
particularly  true  with  reference  to  the  starch  used,  as 
starch  rapidly  absorbs  moisture,  and  even  though  in 
perfect  condition  when  it  left  the  starch  factory,  may 
have  absorbed  sufficient  moisture  during  transit  to  be 
unsuitable  for  the  manufacture  of  baking  powder. 

To  introduce  wet  starch  in  the  manufacture  of  baking 
powder  would  have  the  same  effect  as  to  pour  water 
upon  the  powder  itself.  The  powder  would  be  spoiled 
at  once,  before  reaching  the  consumer.  This  same  pre- 
caution with  reference  to  moisture  must  be  taken  with 
reference  to  the  other  ingredients,  as  these  are  frequently 
shipped  in  rainy  weather  and  in  leaky  cars. 

Then,  too,  it  is  necessary  to  analyze  all  the  ingredients 
for  other  accidental  impurities  which  may  have  been 
introduced.  Chemical  analysis  is  always  carried  out  to 
make  sure  that  heavy  metals,  and  other  objectionable 
substances,  are  absent  from  each  ingredient.- 

MANUFACTURING  APPLIANCES 


manufacturing  appliances  in  use  vary  accord- 
ing  to  the  size  of  the  plant  and  the  progressiveness 
of  the  manufacturer.  The  object  of  these  should  be  not 
only  increased  convenience,  but  above  all,  the  highest 
order  of  sanitation.  Baking  powder  is  a  food  product 


so  Domestic  Science  ^fext  Book 

and  the  progressive  manufacturer  treats  it  as  such.  He 
insists  on  the  most  modern  sanitary  buildings,  free  from 
dust,  flooded  with  sunlight  and  fitted  with  the  latest 
specially-constructed  machinery,  so  that  none  of  the 
ingredients  nor  the  powder  itself  ever  comes  in  contact 
with  the  human  hand.  This  perfect  protection  should 
be  demanded  in  every  food  product.  The  machinery 
in  such  a  building  consists  of  tightly  enclosed  elevators 
and  conveyors  so  constructed  that  the  powder  is  com- 
pletely protected  from  moisture  and  contamination. 
Large,  almost  airtight  bins  are  used  for  temporary 
storage  of  the  ingredients,  which  empty  directly  into 
special  containers  standing  on  modern,  accurate  scales. 
A  single  container  is  used  for  each  ingredient  and  no 
other  substance  ever  enters  it.  These  are  emptied  by 
gravity  into  the  mixers  through  fine  screens,  so  that 
any  lumps  are  removed.  These  tightly  closed  mixers 
contain  many  flights  of  conveyors  working  in  different 
directions,  so  that  all  the  ingredients  are  perfectly  mixed. 
From  the  mixer  the  powder  passes  by  gravity  into  screw 
conveyors,  which  carry  it  to  the  automatic  filling  and 
weighing  machines  (a  further  sanitary  protection), 
where  it  is  weighed  into  the  can.  There  then  remains 
the  labeling  of  the  cans  and  the  boxing  and  packing  to 
make  it  ready  for  shipment.  The  modern  manufacturer 
of  baking  powder  pays  strict  attention  to  the  health  and 
hygiene  of  his  employes.  They  are  clothed  in  white 
uniforms  and  required  to  keep  scrupulously  clean. 


Domestic  Science  TVx/  Book  Page  31 

THE  USE  OF  BAKING  POWDER 

THE  use  of  baking  powder  has  become  very  general 
throughout  the  United  States.  The  Memorial 
of  the  American  Baking  Powder  Association  presented 
in  Congress  in  1900  shows  that  at  that  time  there  was 
produced  annually  baking  powders  of  the  different 
types,  as  follows: 

Tons  used  per  annum  Mfg.   concerns 

Alum 50,000  544  alum  and  alum-phosphate 

Cream  of  tartar.  .  .  .    9,000  10 

Phosphate     300  1 

The  directions  for  the  use  of  baking  powder  in  general 
call  for  two  heaping  teaspoonsful  to  a  quart  of  flour. 
This  amount  is  unnecessary  with  the  stronger  powders, 
and  makes  a  poorer  instead  of  a  better  biscuit.  The 
housewife  will  obtain  better  results  if  she  uses  the 
smaller  proportion  called  for  in  the  directions  given  by 
the  manufacturer.  With  the  stronger  baking  powders 
one  heaping  teaspoonful  to  a  quart  of  flour  is  a  great 
sufficiency.  To  use  more  than  directed  means  to  intro- 
duce an  unnecessary  amount  of  the  residues  in  the 
finished  food. 

HOW  TO  MEASURE 

ALWAYS  measure  the  baking  powder  by  the  level 
teaspoonful.    Scrape  the  straight  edge  of  a  knife 
across  the  spoon,  keeping  the  blade  pressed  to  the  sides 
of  the  bowl.    In  this  way  you  will  always  get  the  same 
amount. 


Page  32  Domestic  Science  °fext  Book 

A  rounding  teaspoonful  =  2  level  teaspoonsful. 
A  heaping    teaspoonful  =-•  4>  level  teaspoonsful. 

One  cannot  expect  to  get  the  same  result  each  time 
she  cooks,  unless  she  is  accurate. 

CARE  OF  BAKING  POWDER 

BAKING  Powder  should  always  be  kept  in  a  dry, 
cool  place.  We  have  seen  in  the  study  of  soda 
that  heat  alone  will  cause  this  ingredient  to  lose  a  portion 
of  its  gas ;  hence,  it  is  essential  that  the  finished  powder 
should  be  kept  in  a  cool  place.  It  has  also  been  seen 
that  moisture  from  any  source  will  bring  about  the 
reaction  between  the  soda  and  "acid,"  which  it  is  de- 
sired should  take  place  only  in  the  dough.  These  pre- 
cautions in  storage  should  be  taken  even  before  the  can 
is  opened. 

The  cans  used  for  baking  powder  are  not  hermet- 
ically sealed,  and  moisture  from  the  air  will  gradually 
work  its  way  into  them.  All  baking  powders  will  spoil 
if  subjected  to  moist  conditions  of  storage.  The  absurd 
claim  of  some  manufacturers  that  their  goods  will  not 
spoil  is  an  insult  to  the  intelligence  of  the  consumer. 
If  moisture  will  not  spoil  the  baking  powder  when  it 
is  in  the  can,  moisture  will  not  activate  the  bakng  pow- 
der (set  free  the  carbon  dioxid)  when  water  or  milk 
is  added  to  the  dough.  If  a  manufacturer  truthfully 
represents  that  his  baking  powder  will  not  spoil,  then 
he  is  selling  something  that  is  useless. 


Domestic  Science  T^ext  Book  Page  33 

SELF-RISING  FLOUR 

SELF-RISING  flour  is  nothing  more  than  a  mixture 
of  flour  and  salt  with  soda  and  an  "acid"  ingredient, 
or  in  other  words,  with  ingredients  such  as  are  used 
in  making  a  baking  powder.  This  mixing  is  almost 
done  without  any  chemical  control  of  the  purity  or 
strength  of  the  ingredients  or  of  the  proportioning  of 
the  ingredients.  The  soda  and  "acid"  are  purchased 
of  the  manufacturers,  with  a  formula  for  mixing  them. 
The  formula  is  never  changed,  no  matter  how  much 
the  purity  or  strength  of  the  ingredients  may  vary.  Such 
a  product  subjects  the  user  thereof  to  every  inconven- 
ience and  disappointments  as  to  flavor  and  color  in  the 
finished  food,  such  as  would  result  from  the  use  of  the 
cheapest  baking  powder,  manufactured  without  chem- 
ical control.  Inasmuch  as  excessive  quantities  of  the 
soda  and  acid  are  frequently  added,  the  housewife  is 
also  preparing  food  containing  excessive  amounts  of 
residue,  when  she  uses  self-rising  flour. 

Because  of  the  large  amount  of  water  contained  in 
flour,  and  the  lack  of  protection  from  atmospheric  mois- 
ture through  the  use  of  cloth  bags  as  containers,  the 
keeping  qualities  of  the  self -rising  mixture  are  seriously 
impaired. 


Page  34 


Domestic  Science  Text  Book 


Harrison's  Apparatus 


Domestic  Science  "Text  Book Page  35 

CHAPTER  V 

THE  DETERMINATION  OF  AVAILABLE 
CARBON  DIOXID 

MR.  BENJAMIN  HARRISON  has  devised  the 
following  rapid  volumetric  method  for  this  deter- 
mination:*     (See  cut.) 

"In  determining  the  percentage  of  available  carbon 
dioxid  in  a  baking  powder,  one-half  gram  of  the  sample 
is  weighed  into  the  small  flask  which  is  then  put  in 
place  on  the  apparatus.  The  stopcock  is  now  turned 
so  as  to  connect  the  flask  with  the  eudiometer,  and  the 
gases  put  under  atmospheric  pressure  by  bringing  the 
saturated  salt  solution  in  the  leveling  bulb  even  with 
the  solution  in  the  eudiometer.  The  stopcock  is  now 
turned  so  as  to  connect  with  the  tube  leading  into  the 
air,  and  the  gases  in  the  eudiometer  driven  out  by  rais- 
ing the  leveling  bulb.  The  stopcock  is  turned  again 
so  as  to  connect  the  flask  and  eudiometer,  and  the  level- 
ing bulb  lowered  to  the  table,  giving  a  slight  vacuum 
in  the  flask. 

"Two  cubic  centimeters  of  previously  boiled,  distilled 
water  are  now  run  into  the  flask  from  the  small  grad- 
uated burette,  and  the  apparatus  shaken  or  rotated  so 
as  to  mix  the  water  thoroughly  with  the  powder.  Heat 


^Proceedings  of  the  Seventeenth  Annual  Convention  of  the  As- 
sociation of  American  Dairy  Food  and  Drug  Officials,  1913,  p.  158. 


Page  36  Domestic  Science  T^ext  Book 

is  then  gently  applied  to  the  flask  until  the  water  just 
reaches  the  boiling  point.  Care  must  be  taken  here  not 
to  char  the  powder  or  boil  off  the  water.  The  whole 
apparatus  is  allowed  to  cool  to  room  temperature,  the 
gas  in  the  flask  and  eudiometer  brought  under  atmos- 
pheric conditions  by  raising  the  solution  in  the  leveling 
bulb  and  its  volume  read.  The  temperature  and  baro- 
metric pressure  are  also  taken. 

"We  now  have  a  volume  which  represents  the  gas 
from  the  baking  powder  plus  two  cubic  centimeters  from 
the  water  added.  Experiment  has  shown  that  the  equiv- 
alent of  one  cubic  centimeter  of  carbon  dioxid  is  retained 
by  the  water,  and  powder  in  the  small  flask,  so  if  we 
subtract  one  cubic  centimeter  from  the  observed  reading 
we  have  the  available  gas  equivalent  of  the  sample  taken. 
The  corrected  volume  of  the  gas  is  reduced  to  0°  C. 
and  760mm.  pressure,  and  the  number  of  cubic  centi- 
meters found  multiplied  by  the  weight  of  one  cubic 
centimeter  of  carbon  dioxid,  giving  the  weight  of  carbon 
dioxid  in  the  sample.  This  weight,  if  divided  by  five- 
tenths  and  multiplied  by  one  hundred,  gives  the  per- 
centage of  available  carbon  dioxid  in  the  sample. 

"In  the  Journal  of  the  American  Chemical  Society, 
Vol.  31,  February,  1909,  on  page  237,  is  a  table  by 
Prof.  S.  W.  Parr,  giving  the  weight  of  one  cubic  centi- 
meter of  carbon  dioxid  at  various  temperatures  and 
pressures,  which  saves  considerable  calculation." 


Domestic  Science  TW/  Book  Pase  37 

The  above  method  has  been  found  to  be  accurate  to 
within  one  or  two-tenths  of  1%,  and  is  sufficiently  accu- 
rate for  almost  all  work. 

A  more  accurate  method  is  the  one  in  which  the 
amount  of  gas  set  free  is  absorbed  by  a  caustic  potash 
solution,  or  by  soda  lime  and  then  weighed. 

ABSORPTION  METHOD* 

THIS  method  is  carried  out  by  the  use  of  Knorr's 
apparatus,  the  potassium  hydroxide  solution  used 
has  a  specific  gravity  1.27.  This  is  prepared  by  dis- 
solving 36.8  grams  of  solid  potassium  hydroxide  in  100 
cubic  centimeters  of  water.  The  apparatus  is  shown 
in  the  accompanying  illustration.  The  solution  in  "F" 
and  "J"  is  the  potassium  hydroxide  solution  just  men- 
tioned. "E"  and  "H"  contain  concentrated  sulphuric 
acid.  "C"  contains  soda  lime.  The  small  tubes  of  "E" 
and  "F"  are  filled  with  calcium  chloride  and  "L"  con- 
tains layers  of  calcium  chloride,  and  soda  lime. 

The  analysis  is  conducted  as  follows: 

Place  7/10  of  a  gram  of  the  baking  powder  in  the 
perfectly  dry  distilling  flash  "A."  Weigh  the  tubes 
"F"  in  which  the  carbon  dioxid  is  to  be  absorbed  and 
"H"  and  attach  to  the  apparatus. 


*Methods    of    Analysis,    Association    of    Official    Agricultural 
Chemists.    Bureau  of  Chemistry  Bulletin  No.  107  (Revised),  p.  169. 


Page  38 


Domestic  Science  tfext  Book 


Modified   Knorr  Apparatus 


Domestic  Science  T^ext  Book  Page  39 

Nearly  fill  the  tube  "B"  with  recently  boiled  distilled 
water  and  place  the  tube  "C"  in  position.  Then  start 
the  aspirator  at  such  a  rate  that  the  air  passes  through 
the  Liebig  bulbs  at  about  the  rate  of  2  bubbles  per  sec- 
ond. Open  the  stopcock  of  the  funnel  "B"  and  allow 
the  water  to  run  slowly  into  the  flask,  care  being  taken 
that  the  evolution  of  gas  shall  be  so  gradual  as.  not  to 
materially  increase  the  current  through  the  Liebig  bulb. 

After  all  the  water  has  been  introduced,  continue 
the  aspiration  and  gradually  heat  the  contents  of  the 
flask  to  boiling,  the  cock  in  tube  "B"  being  closed.  Con- 
tinue the  boiling  for  a  few  minutes.  After  the  water 
has  begun  to  condense  in  "D,"  remove  the  flame,  open 
the  valve  in  tube  "B"  and  allow  the  apparatus  to  cool 
while  continuing  the  aspiration.  Air  should  be  drawn 
through  the  apparatus  for  a  considerable  time  in  order 
to  completely  remove  all  the  carbon  dioxid  from  flask 
"A."  The  whole  operation  should  take  at  least  two 
hours.  Tubes  "F"  and  "H"  are  then  removed  from 
the  apparatus  and  weighed.  The  total  increase  in  weight 
is  due  to  the  carbon  dioxid  set  free  from  the  baking 
powder. 


Page  40  Domestic  Science  "Text  Book 

CHAPTER  VI 

COST  OF  BAKING  POWDER 

THE  cost  of  any  material  used  for  a  piece  of  work 
must  be  figured  on  the  cost  of  that  material  for 
a  single  unit  of  the  work  to  be  done. 

So  account  must  be  taken  in  the  case  of  baking  pow- 
der, both  of  the  cost  per  pound  of  the  powder  itself  and 
the  amount  of  work  it  will  do.  The  price  per  pound 
varies  from  10  cents  to  50  cents.  The  amount  of  work 
each  powder  will  do  can  be  compared  after  a  determina- 
tion of  the  amount  of  available  gas,  or  after  scientific 
comparative  bakings.  Neither  of  these  is  necessary, 
however.  We  may  take  it  for  granted  that  the  manu- 
facturer in  giving  directions  for  the  use  of  his  powder 
has  taken  the  strength  into  consideration  in  stating  what 
amount  of  baking  powder  should  be  used.  The  direc- 
tions uniformly  give  the  amount  to  be  used  to  leaven 
one  quart  of  sifted  flour.  The  amount  of  baking  powder 
to  be  used  as  stated  on  the  labels  varies  from  one  heap- 
ing teaspoonful,  or  two  rounded  teaspoonfuls,  to  two 
heaping  teaspoonsful.  Some  manufacturers  use  the 
term  "rounded  teaspoonful"  and  others  "heaping  tea- 
spoonful."  One  can  always  compare  these  by  remem- 
bering that — 

2  level  teaspoonsful  =   1   rounded  teaspoonful. 
4  level  teaspoonsful  =  1   heaping  teaspoonful. 


Domestic  Science  T^ext  Book Page  41 

An  example  of  the  difference  in  cost  of  baking  pow- 
der is  the  following: 

"A."  sells  baking  powder  at  50  cents  per  pound  and 
directs  that  you  use  2  heaping  teaspoonsful  to  the  quart 
of  flour. 

"B."  sells  baking  powder  at  25  cents  per  pound  and 
directs  that  you  use  2  rounded  teaspoonsful  to  the  quart 
of  flour. 

What  does  it  cost  to  leaven  a  quart  of  flour  with 
"A.'s"  powder  as  compared  with  that  of  "B.'s"? 

Answer — Four  times  as  much. 

CAUTION — Never  use  more  baking  powder  than  rec- 
ommended by  the  manufacturer.  By  following  direc- 
tions you  will  get  the  best  results. 

BAKING  POWDER  A  NECESSITY 

IN  conclusion  it  should  be  stated  that  baking  powder 
has  done  much  to  lighten  and  decrease  the  hours  of 
labor  of  the  housewife.  It  has  made  possible  the  easy 
and  rapid  production  of  many  new,  dainty  and  nutri- 
tious foods.  The  best  powder  may  be  purchased  at 
a  moderate  price  and  the  wholesomeness  of  the  food 
prepared  therefrom  need  not  be  questioned.  That  it  is 
a  convenience  that  cannot  be  dispensed  with  is  appre- 
ciated most  by  those  who  use  it  most  intelligently. 


Page  43  Domestic  Science  "Text  Book 


QUESTIONS 

1.  Name  two  common  leavening  agents. 

2.  What  is  yeast? 

3.  What  is  baking  powder? 

4.  What  is  the  active  leavening  agent  produced  by  both  yeast 

and  baking  powder? 

5.  Name  three  disadvantages  in  the  use  of  yeast. 

6.  Name  three  advantages  in  the  use  of  baking  powder. 

7.  What  are  the  natural  sources  of  carbon  dioxid  gas? 

8.  What  is  soda? 

9.  How  is  it  made? 

10.  What  happens  when  soda  is  heated? 

11.  Why  is  its  use  alone  unsatisfactory  as  a  leavening  agent? 

12.  Why  is  the  use  of  ammonium  carbonate  unsatisfactory  as   a 

leavening  agent? 

13.  What  is  the  purpose  of  magnesium  carbonate  in  cheap  baking 

powders  ? 

14.  What  substance  with  soda  is  necessary  in  baking  powder  for 

the  production  of  carbon  dioxid? 

15.  What  two  conditions  must  the  acid  and  alkali  fulfill? 

16.  Name  an  acid  commonly  found  in  so-called  cream  of  tartar 

baking  powder. 

17.  Name  two  acid  salts  in  baking  powder. 

18.  Name  a  salt  which  acts  as  an  acid  to  soda  but  which  is  neither 

an  acid  nor  an  acid  salt. 

19.  What  substances  other  than  acid  and  soda  are  used  in  baking 

powder  ? 

20.  What  is  the  source  of  tartaric  acid? 

21.  How  is  it  purified? 

22.  How  is  cream  of  tartar  obtained? 

23.  What  are  the  sources  of  calcium  acid  phosphate  ? 

24.  What  is  the  process  of  making  bone  phosphate? 

25.  Why  is  bone  phosphate  preferable  to  rock  phosphate  ? 


Domestic  Science  Text  Book  rage  43 

26.  What    advantage    has     granular    phosphate     over    powdered 

phosphate  ? 

27.  In  what  powder  is  the  phosphate  of  the  granular  type? 

28.  What  is  alum? 

29.  What  is  the  so-called  "alum"  of  baking  powder? 

30.  What  is  the  difference  between  these  two  ? 

31.  Why  is  the  latter  called  "alum"? 

32.  How  is  it  made? 

83.     What  three  purposes  does  starch  serve  in  baking  powder? 

34.  What  per  cent  of  gas  do  good  baking  powders  produce? 

35.  What  are  the  most  widely  known  baking  powders  that  contain 

white  of  egg? 

36.  What  is  dried  white  of  egg? 

37.  Does  it  increase  the  efficiency  of  baking  powder? 

38.  If  so,  to  what  extent? 

39.  How  much  egg  albumen  is  generally  used  in  baking  powder? 

40.  What  other  purpose  does  egg  albumen  serve  in  baking  powder  ? 

41.  Describe  the  water-glass  test. 

42.  To  what  use  is  this  'test  put? 

43.  What  company  uses  this  test  most  in  testing  its  goods  on  the 

grocer's  shelves. 

44.  What  must  be  present  in  baking  powder  to  make  the  water- 

glass  test? 

45.  What  constitutes  the  difference  between  the  classes  of  baking 

powder  ? 

46.  What  four  items  should  be  considered  in  the  choice  of  an  acid 

ingredient  ? 

47.  Why  should  chemically  equivalent  amounts  of  acid  and  alkali 

be  used  in  baking  powder? 

48.  What  is  formed  by  the  action  of  tartaric  acid  on  soda  ? 

49.  What  is  formed  by  the  action  of  cream  of  tartar  on  soda? 

50.  What  is  formed  from  the  action  of  calcium  acid  phosphate  on 

soda? 

51.  What  is  formed  by  the  action  of  "alum"  on  soda? 


Page  44  Domestic  Science  *¥ext  Book 

52.  If  the  different  substances  be  mixed  with  soda  in  proper  pro- 

portions,   which    mixture    will    produce    the    least    amount 
of  gas? 

53.  How  much? 

54.  How  much  gas  will  the  mixture  of  "alum"  and  soda  produce? 

55.  How  much  gas  will  the  mixture  of  calcium  acid  phosphate  and 

soda  produce? 

56.  What  is  the  purpose  of  starch  in  baking  powder  in  relation 

to  the  amount  of  gas? 

57.  What  baking  powder  contains  no  starch? 

58.  What  class  of  baking  powders  leave  the  greatest  amount  of 

objectionable  residue?     Name  four  such  powders. 

59.  Name  two  baking   powders   having   only   "alum"   as   an   acid 

ingredient. 

60.  Is    "alum"    present   in    foods   prepared    from   "alum"   baking 

powder  ? 

61.  Do  "alum"  baking  powders  injure  digestion? 

62.  What  is  the  final  decision  of  the  Remsen  Board  as  to  the  harm- 

fulness  of  "alum"  baking  powder? 

63.  What  is  the  nature  of  the  residue  from  every  baking  powder 

when  taken  in  very  large  quantities? 

64.  What  residue  is  left  from  cream  of  tartar  baking  powders? 

65.  What  residue  is  left  from  phosphate  baking  powder? 

66.  What  residue  is  left  from  "alum"  baking  powder  ? 

67.  What  baking  powder  is  most  liable  to  produce  catharsis  ? 

68.  Which  then  is  the  least  desirable  from  a  health  standpoint? 

69.  Is  the  cry  against  "alum"  in  baking  powders  based  on  preju- 

dice or  fact? 

70.  What  is  the  effect  of  tartrates  on  the  kidneys  ? 

71.  What  is  the  effect  on  other  baking  powder  residues? 

72.  Why  are  there  not  more  straight  phosphate  baking  powders  on 

the  market? 


Domestic  Science  T^ext  Book  Page  45 

73.  What  is  the  most  prominent  baking  powder  of  the   straight 

phosphate  class? 

74.  What  causes  baking  powder  to  spoil  in  the  cans  ? 

75.  What  baking  powders  keep  best  of  all? 

76.  What  causes   the    difference    in    the    speed    action   of   baking 

powder  ? 

77.  What  is  the  disadvantage  in  the  use  of  straight  phosphate  and 

cream  of  tartar  baking  powders  ? 

78.  Name  three  so-called  pure  cream  of  tartar  baking  powders  that 

contain  tartaric  acid. 

79.  Name  a  cream  of  tartar  baking  powder. 

80.  What  is  the  disadvantage  in  the  use  of  straight  "alum"  baking 

powder  ? 

81.  What    is    the    best    and    most    common    type    of    combination 

powders  ? 

82.  Which  is  the  leading  powder  of  this  type  containing  sufficient 

phosphate  ? 

83.  What  is  its  action? 

84.  Why  is  chemical  supervision  necessary  in  the  manufacture  of 

baking  powder? 

85.  What  would  be  the  result  of  the  use  of  wet  starch  in  the 

manufacture  of  baking  powder? 

86.  What  attention  should  be  given  to  sanitation  in  baking  powder 

factories  ? 

87.  What  class  of  baking  powder  is  in  widest  use? 

88.  What  is  meant  by  level  teaspoonful? 

89.  What  is  equivalent  to  a  "rounding"  teaspoonful? 

90.  What  is  equivalent  to  a  "heaping"  teaspoonful? 

91.  Why  should  baking  powder  be  kept  in  a  cool  dry  place? 

92.  Why  will  baking  powder  eventually  spoil  ? 

93.  What  caution  should  be  borne  in  mind  in  the  use  of  baking 

powder  ? 

94.  What  has  baking  powder  done  for  the  housewife? 


Page  46  Domestic  Science  ^fext  Book 

ANSWERS 

1.  Yeast  and  baking  powder. 

2.  Yeast  is  a  microscopic  plant  which  in  the  leavening  process 

breaks  up  sugars  into  carbon  dioxid  gas  and  alcohol. 

3.  Baking  powder  is  a  mixture  of  substances  which  produce  car- 

bon dioxid  gas  by  chemical  action. 

4.  Carbon  dioxid  gas. 

5.  (a)  The  different  fermentations  resulting  from  yeast  produce 

different  and  sometimes  objectionable  flavors. 

(b)  It  takes  several  hours  for  fermentation  to  take  place  before 
the  dough  can  be  put  in  the  oven. 

(c)  Yeast  does  not  act  readily  in  the  presence  of  large  quan- 
tities of  butter,  lard  or  eggs. 

6.  (a)  With  a  good  baking  powder  the  action  is  always  the  same, 

and  therefore  the  flavors  are  always  the  same. 

(b)  The  gas  is  given  off  at  once  on  the  addition  of  water,  or 
in  the  oven;  there  is  no  delay. 

(c)  The  action  takes  place  readily  in  the  presence  of  butter, 
lard  or  eggs. 

7.  Carbon  dioxid  occurs  in  nature  combined  with  metals,  as  car- 

bonates, such  as  chalk,  marble  and  limestone.      It  is  set 
free  from  these  by  means  of  acids. 

8.  Soda  is  saleratus  or  cooking  soda,  sometimes  called  the  alkali 

of   baking   powder.     It    is    chemically   known    as    sodium 
bi-carbonate. 

9.  Soda  is  made  from  common  salt  by  the  action  of  acid  am- 

monium carbonate. 

10.  On  heating,  soda  breaks  up,  giving  off  carbon  dioxid  gas  and 

leaving  normal  sodium  carbonate. 

11.  Normal  sodium  carbonate  is  left  in  the  food.     It  produces  an 

objectionable  flavor  in  the  food  and  colors  it  yellow. 

12.  Ammonium  carbonate  leaves  traces  of  ammonia  gas  in  the  food. 

13.  Magnesium  carbonate  is  used  as  a  filler  because  of  its  extreme 

light  weight.     The   great  volume  of   such  powder   often 


Domestic  Science  tfext  Book  Page  47 

makes  the  purchaser  think  she  is  getting  more  baking 
powder. 

14.  An  acid  or  an  acid-acting  salt  to  release  the  carbon  dioxid  gas. 

15.  The   acid   and   alkali   should   be   dry   substances   and   dissolve 

readily  in  water. 

16.  Tartaric  acid. 

17.  Calcium  acid  phosphate  and  cream  of  tartar. 

18.  Sodium  aluminum  sulphate,  sometimes  called  "alum." 

19.  Cornstarch  and  white  of  egg. 

20.  Tartaric  acid  is  made  from  argol,  the  sediment  from  wine  vats. 

21.  It  is  purified  by  treating  with  chalk  and  calcium  chloride,  and 

filtering  the  resulting  mixture  of  the  calcium  salt.  The 
calcium  tartrate  is  dissolved  in  sulphuric  acid,  after  which 
the  solution  is  filtered  and  the  tartaric  acid  allowed  to 
crystallize. 

22.  Cream  of  tartar  is   also  obtained  from  argol,  the  source   of 

tartaric  acid.  The  chemical  treatment  of  this,  however, 
differs  from  that  of  tartaric  acid. 

23.  Calcium   phosphate    is    obtained    from   the    bones    of    healthy 

cattle  and  sometimes  from  natural  rock. 

24.  The  bones  are  burned  and  then  treated  with  sulphuric  acid. 

The  solution  is  purified  by  filtration,  crystallized  and  dried. 

25.  Phosphate  from  bone  is  preferable  to  that  from  rock  because 

it  does  not  contain  the  harmful  impurities,  fluorides, 
present  in  rock. 

26.  Granular  phosphate  makes  a  baking  powder  which  will  keep 

better  than  that  made  from  the  powdered  phosphate. 
Granular  phosphate  is  more  expensive. 

27.  In  Calumet  Baking  Powder. 

28.  Alum  is  potassium  aluminum  sulphate  with  water  of  crystal- 

lization. 

29.  The   so-called   "alum"   is   a  mixture   of   sodium  sulphate  and 

aluminum  sulphate  with  no  water  of  crystallization. 


Page  48  Domestic  Science  'Text  Book 

-30.  Alum  contains  potassium  and  water  of  crystallization.  It  is 
used  as  a  medicine.  The  so-called  "alum"  of  baking 
powder  contains  neither  potassium  nor  water  of  crystal- 
lization and  has  no  medicinal  use. 

31.  The  latter  is  called  "alum"  because  some  food  commissioners 

thought  this  word  better  showed  the  general  character- 
istics of  the  substance  to  the  public. 

32.  It  is  made  by  mixing  solutions  of  sodium  sulphate  and  alumi- 

num sulphate,  concentrating  the  mixture  and  fusing  the 
resulting  mass. 

33.  Starch  serves  three  purposes  in  baking  powder: 

(a)  To  separate  the  soda  and  the  acid  mechanically. 

(b)  To  absorb  water  from  the  air  and  prevent  deterioration 
of  the  baking  powder. 

(c)  To   dilute   the   baking   powder    to    a    strength    convenient 
for  purposes  of  household  measurement. 

34.  Good  baking  powders  produce  from  12%  to  15%  available  gas. 

35.  Calumet  and  Crescent  Baking  Powders. 

36.  Dried  white  of  egg  is  the  dried  white  of  fresh  hen's  eggs. 

37.  It  does  materially  increase  the  efficiency  of  the  baking  powder. 

38.  From  2l/2  to  3  2/10%  when  used  in  strong  powder. 

39.  Baking  powders  generally  contain  15/100  of  1%. 

40.  Egg  albumen  furnishes  a  means  of  estimating  the  strength  of 

the  baking  powder. 

41.  Take  an  ordinary  drinking  glass  holding  one-half  pint,  or  in 

other  words,  the  quantity  that  is  usually  known  in  the 
household  as  "one  cupful."  All  that  is  needed  is  this 
empty  glass,  which  must  be  dry,  an  ordinary  teaspoon 
and  a  little  water  of  the  ordinary  room  temperature  (not 
ice  water  nor  hot  water)  ;  place  two  level  teaspoonsful  of 
the  powder  in  the  dry  glass,  to  which  add  the  same  quan- 
tity (two  teaspoonsful)  of  water,  quickly;  stir  rapidly  for 
a  moment  (while  counting  five),  just  long  enough  to  thor- 
oughly moisten  the  powder;  remove  the  spoon  and  watch 


Domestic  Science  Text  Book  Page  49 

the  mixture  rise.     Note  the  action  of  the  powder. 

42.  This  test  is  used  to  insure  the  freshness  of  the  grocer's  stock 

and  protect  the  consumer.  Deteriorated  goods  are  detected 
by  this  test  and  replaced  with  fresh  by  the  manufacturers 
free  of  charge. 

43.  The  Calumet  Baking  Powder  Co. 

44.  White  of  egg  must  be  present  before  the  test  can  be  made. 

45.  The  difference  between  baking  powders   is   in   the   ''acid"  or 

"acids"  used  to  release  the  carbon  dioxid  from  the  soda 
and  in  the  proportions  of  the  same. 

46.  The  four  items  to  be  considered  in  the  selection  of  an  acid 

for  a  baking  powder  are  the  healthfulness  of  the  residues, 
the  amount  of  gas  it  will  release,  the  keeping  qualities  of 
the  resulting  baking  powder  and  the  speed  of  action. 

47.  Chemically  equivalent  amounts  of  acid  and  alkali  should  be 

used  in  baking  powder  because  an  excess  of  acid  leaves 
that  much  acid  unchanged  in  the  food  and  an  excess  of 
soda  causes  an  alkaline  flavor  and  a  yellow  color  in  the 
foods. 

48.  Sodium  tartrate,  carbon  dioxid  gas  and  water. 

49.  Rochelle  salts,  carbon  dioxid  gas  and  water. 

50.  Calcium  phosphate,  sodium  acid  phosphate,  carbon  dioxid  gas 

and  water. 

51.  Aluminum  hydrate,  sodium  sulphate,  and  carbon  dioxid  gas. 

52.  Cream  of  tartar  and  soda  sets  free  the  least  amount  of  gas. 

53.  16.2%. 

54.  26.7%. 

55.  25.6%. 

56.  Starch  is  then  added  to  baking  powder  to  reduce  the  amount  of 

gas  given  off.  Without  starch,  too  much  gas  would  be 
evolved  in  the  case  of  "alum"  and  phosphate  powders. 

57.  Shillings'. 

58.  Cream  of  tartar  baking  powder  leaves  the  largest  amount  of 

objectionable    residues;    77.2%    Rochelle    salts    when    no 


Page  50  Domestic  Science  ^ext  Book 

starch  is  present;   57.2%    Rochelle   salts   is   left  from  a 
powder  producing  12%  of  gas.     Shillings',  Royal,  Price's 
and  Cleveland  Baking  Powders. 
69.     Bon  Bon  and  Good  Luck. 

60.  No. 

61.  No. 

62.  Alum  baking  powders  are  no  more  harmful  than   any   other 

baking  powders. 

63.  A  saline  cathartic. 

64.  Rochelle  salts,  which  act  as  a  saline  cathartic  and  a  diuretic 

as  well. 

65.  Sodium  phosphate,  a  mild  cathartic. 

66.  Sodium  sulphate,  a  mild  cathartic. 

67.  Cream  of  tartar   or  tartaric  acid  baking  powders   are  twice 

as  likely  to  produce  catharsis  as  any  other  baking  powder. 

68.  Cream  of  tartar  or  tartaric  acid  powders. 

69.  The  cry  against  "alum"  is  based  on  prejudice. 

70.  Tartrates  produce  nephritis. 

71.  The  residues  from  other  baking  powders  have  been  declared 

to  be  non  injurious. 

72.  Because   straight  phosphate   baking   powders   keep   only    for 

a  short  time. 

73.  Rumford  Baking  Powder. 

74.  Moisture  from  the  air  or  from  any  other  source,  or  excessive 

heat. 

75.  The  baking  powders  containing  "alum"  keep  the  best  of  all. 

76.  The  difference   in  the  solubility   of  the   acid   constituents   in 

water. 

77.  Straight  phosphate  and  cream  of  tartar  powders  give  off  their 

gas  quickly,  therefore  are  liable  to  cause  fallen  biscuits 
if  the  oven  is  not  at  the  optinimum  temperature. 

78.  Cleveland,  Royal  and  Price's. 

79.  Shillings'. 

80.  Straight  alum  baking  powder  gives  off  practically  no  gas  in  the 


Domestic  Science  T^ext  Book  Page  51 

cold  resulting  in  small,  heavy  and  poorly  leavened  biscuits 
if  placed  in  too  hot  an  oven. 

81.  "Alum"-phosphate  is  the  best  and  most  common  type  of  com- 

bination powders. 

82.  Calumet  Baking  Powder. 

83.  The    best    "alum"-phosphate    powders    give    off    the    proper 

amount  of  gas  in  the  cold  with  sufficiently  large  amount 
of  additional  gas  when  placed  in  the  oven.  They  keep 
best  and  produce  better  results  in  cooking. 

84.  To  insure  a  perfect  product,  always   of  the   same  strength, 

neither  acid  nor  alkaline,  and  above  all  to  insure  its  purity. 

85.  Wet    starch    in    baking    powder    would    cause    its    immediate 

spoilage. 

86.  Baking  Powder  is  used  in  the  preparation  of  foods,  and  there- 

fore   its    manufacture    should    be    carried    on    under    the 
strictest  sanitary  conditions. 

87.  "Alum"-phosphate  powders  have  the  widest  use. 

88.  A   straight    knife    blade    moved    over    the    spoon    filled    with 

powder,  keeping  the  blade   pressed   to  the   sides   of   the 
bowl,  leaves  a  level  teaspoonful. 

89.  Two  level  teaspoonsful  are  equivalent  to  a  rounding  teaspoon- 

ful. 

90.  Four  level  teaspoonsful  are  equivalent  to  a  heaping  teaspoon- 

ful. 

91.  Baking  powder  should  be  kept  in  a  cool,  dry  place.     Moisture 

will  spoil  the  powder,  and  heat  decompose  the  soda. 

92.  Baking  powder  will  eventually  spoil  because  the  cans  are  not 

hermetically  sealed  and  moisture  enters  from  the  air. 

93.  One  should  always  follow  the  directions  given  by  the  manu- 

facturers, using  no  more  than  is  recommended,  for  different 
baking  powders  are  of  different  strengths. 

94.  Baking  powder  has  lightened  and  decreased  the  labor  of  the 

housewife.     It  has  made  possible  the  easy  and  rapid  pro- 
duction of  dainty  and  healthful  foods. 


PHOTOGRAPHIC   REPRODUCTION    OF    BULLETIN    NO.  103 
UNITED   STATES    DEPARTMENT   OF  AGRICULTURE 

Page  52 


BULLETIN    OF   THE 


No.  103 


Contribution  from  the  Referee  Board  of  Consulting  Scientific  Experts,  Ira 
Remsen.  Chairman.     April  29,  1914. 

(PROFESSIONAL  PAPER.) 

ALUM  IN  FOODS. 

EXPLANATORY  STATEMENT. 

A  report  on  the  influence  of  aluminum  compounds  on  the  nutrition 
and  health  of  man  has  been  submitted  by  the  Referee  Board  of  Con- 
sulting Scientific  Experts,  in  answer  to  questions  put  to  it  by  the 
department.  The  report  of  the  board  itself,  signed  by  each  member, 
is  brief,  but  it  is  accompanied  by  three  elaborate  reports  giving  the 
results  of  three  sets  of  extensive  experiments  on  human  subjects 
conducted  independently  by  three  members  of  the  board.  To  get 
the  board's  conclusions  before  the  public  at  this  time,  it  is  considered 
advisable  to  publish  its  findings,  but  to  omit  the  extensive  reports 
of  the  three  experimenters,  giving  only  their  final  conclusions. 

QUESTIONS  SUBMITTED  TO  REFEREE  BOARD. 

The  questions  submitted  to  the  board  were  as  follows: 

1.  Do  aluminum  '  compounds,  when  used  in  foods,  affect  injuriously  the  nutritive 
value  of  such  foods  or  render  them  injurious  to  health? 

2.  Does  a  food  to  which  aluminum  compounds  have  been  added  contain  any  added 
poisonous  or  other  added  deleterious  ingredient  which  may  render  the  said  food 
injurious  to  health?    (a)  In  large  quantities?    (6)  In  small  qiiantities? 

3.  If  aluminum  compounds  be  mixed  or  packed  with  a  food,  is  the  quality  or 
strength  of  said  food  thereby  reduced,  lowered,  or  injuriously  affected?    (a)  In  large 
quantities?    (6)  In  small  quantities? 

CHARACTER  OF  EXPERIMENTS  CONDUCTED. 

In  order  to  base  their  report  upon  first-hand  knowledge,  the  board 
instituted  three  sets  of  experiments,  each  independent  of  the  others. 
One  set  of  experiments  was  conducted  by  Dr.  Russell  H.  Chittenden, 
of  the  Sheffield  Scientific  School,  Yale  University,  New  Haven; 
another  by  Dr.  Alonzo  E.  Taylor,  of  the  Medical  School  of  the  Uni- 
versity of  Pennsylvania,  Philadelphia;  and  the  third  by  Dr.  John  H. 
Long,  of  the  Northwestern  University  Medical  School,  Chicago.  In 

>  Aluminum  is  a  synonym  for  aluminium,  the  metal  used  for  cooking  utensils  and  other  implements. 
Alum  or  sodium  aluminum  sulphate  is  a  salt  of  this  metal. 
41042*— 14 


Page  53 


BULLETIN   103,   U.    S.    DEPARTMENT  OF  AGEICULTUKE. 


each  case  tests  were  made  on  healthy  young  men  by  including 
aluminum  in  some  form  in  their  food.  The  food  was  all  carefully 
measured  and  weighed  and  the  amounts  of  its  principal  ingredients 
were  determined  by  analysis.  The  excretions  of  the  men's  bodies 
(both  urine  and  feces)  were  carefully  collected,  examined,  and  ana- 
lyzed. Daily  records  of  body  weight,  temperature,  respiration,  and 
pulse  were  kept  for  each  man,  and  notes  were  made  of  any  unusual 
symptoms.  Any  disturbance  in  health  or  physiological  processes 
was  thus  detected. 

Each  experiment  included  three  periods,  in  the  first  and  last  of 
which  no  aluminum  was  administered.  During  the  middle  period 
aluminum  compounds  were  administered,  the  "dose"  increasing  as 
the  experiment  progressed.  In  this  way  the  effect  of  large  quanti- 
ties was  compared  with  that  of  small  quantities  In  Dr.  Chitten- 
den's  and  Dr  Taylor's  experiments  some  of  the  men  who  served  as 
''control"  subjects  received  no  aluminum  at  any  time,  so  that  any 
disturbances  due  to  other  caused  might  be  checked  up*. 

Dr.  Chittenden's  experiments  included  12  men  and  continued 
from  January  15  to  June  22,  1912.  During '130  days  the  diet  con- 
tained bread  raised  with  an  alum  baking  powder  made  in  the  labo- 
ratory.1 The  dose  of  aluminum  compound  was  increased  from  time 
to  time,  at  first  by  increasing  the  quantity  of  bread  and  later  by  in- 
creasing the  quantity  of  the  baking  powder  used  in  making  the  bread. 
In  this  way  the  alum  2  used  per  man  per  day  was  increased  from 
0.578  gram3 "(8. 920  grains)  at  the  beginning  to  2.287  grams  4  (35.295 
grains)  at  the  close  of  the  dosage  period;  the  actual  aluminum  con- 
tained in  this  dosage  ranged  from  0.065  gram  (1.003  grains)  to  0.257 
gram  (3.966  grains)  per  man  per  day.  Eight  men  used  the  alum 
bread,  while  four  had  no  aluminum  in  their  food. 

Dr.  Long's  experiments  ran  from  February  8  to  June  7,  1911,  and 
included  six  men,  all  of  whom  received  the  dosage.  Baking  powder 
bread  was  not  used,  but  instead  for  40  days  a  mixture  of  the  same 
composition  as  the  residue  left  in  such  bread  by  alum  baking  powder 
was  administered  in  the  form  of  a  powder  in  water  or  milk.  For  30 

>  This  bread  was  made  fresh  every  day  and  contained  in  one  baking  of  two  loaves  approximately 

Sifted  flour quarts..    2 

Baking  powder  (25  per  cent  calcined  alum) heaping  teaspoonfuls. .    4 

Salt,  (approximately  one  rounded  teaspoonful) ounce..    J- 

Butter ....I.... do....    1 

Water,  sufficient  quantity. 

Later  in  the  experiment  a  greater  proportion  of  alum  baking  powder  was  used  in  the  making  of  the  bread 
in  order  to  facilitate  administering  larger  amounts  of  alum. 

*  The  term  "alum"  as  used  under  the  heading  "  Character  of  experiments  conducted  '  refers  to  the  cal- 
cined sodic  aluminic  sulphate  commonly  used  in  alum  baking  powders  and  not  to  the  ordinary  crystallized 
slum. 

'  Equivalent  to  approximately  two-thirds  of  a  level  leaspoonful  of  baking  powder  containing  25  per  cent 
•f  alum.    All  the  figures  Ifi  this  and  succeeding  footnotes  must  of  necessity  be  approximate,  since  teaspoont 
vary  In  size  and  baking  powders  in  composition. 
'Approximately  equivalent  to  2]  level  teaspoonfuls  of  alum  baking  powder. 


Page  54 


ALUM  IN 


days  the  quantity  of  alum  used  was~2  grams1  (30.866  grains)  a  day  for 
each  man;  in  the  next  10  days  the?  dose  was  doubled.  Afterwards 
for  30  days-the  baking  pdwder  residue*  was  treated  so  as  to  wash  out 
everything  except  the  compounds  of  ^aluminum  with  hydrogen  and 
oxygen  (aluminum  hydroxide),  the  dose  at  first  being  the  .amount 
obtained  from  4  grams,2  (61.732  grains)  of  alum  per  man  per  dayr 
which  was  increased  in  the  second  10  days  to  6  grams3  (92.598  grains) 
and  in  the  third  10  days  to  10  grams  (154.330  grains)  of  alum.  Finally, 
in  a  period  of  10  days,  the  dose  was  the  sodium  sulphate  consumed 
when  4  grams  of  alum  were  used,  this  compound  being  the  cathartic 
ingredient  which  is  left  in  bread  by  alum  baking  powder."4 

Dr.  Taylor  conducted  experiments  with  a  squad  of  eight  men  from 
Octobers,  1911,  to  May  10,  1912,  with  an  intermission  from  December 
16  to  January  14.  In  this  case  also  the  powder  was  not  used  in 
bread,  but  was  administered  in  wafers  or  dissolved  in  water.  Six 
of  the  subjects  took  the  aluminum  compounds,  while  the  other  two 
took  milk  sugar,  the  men  themselves  not  knowing  which  they  were 
taking.  There  were  two  groups  of  experiments  in  which  the  whole 
squad  took  part.  In  the  experiments  of  the  first  group,  which  ran 
from  October  8  to  December  16,  tests  were  made  .with  alum  alone. 
The  dose  at  first  was  such  as  to  give  each  man  0.1  gram6  (1.5433 
grains)  of  aluminum  a  day  and  was  increased  from  time  to  time  until 
the  daily  dosetwas  0.298  gram  •  (4.599  grains)  of  aluminum  for  each 
man.  The  second  group  ran  from  January  14  to  May  10.  Tests 
were  made  with  the  residue  from  alum  baking  powder;  tests  were 
also  made  with  certain  aluminum  compounds  (aluminum  hydroxide 
and  aluminum  chloride)  which  may  be  faund  in  the  residues  from 
alum  baking  powders  of  different  kinds,  and  with  sodium  sulphate, 
the  purgative  salt  left  in  bread  by  alum  baking  powders.  Ihe 
smallest  dose  of  the  compounds  containing  aluminum  gave  each  man 
0.227  gram. 7  (3.503  grains)  of  aluminum  a  day,  .while  the  largest  dose 
gave  0.969  gram  8  (14.954  grains)  of  aluminum  a  day.  The  dose  of 
the  purgative  salt  (sodium  sulphate),  in  which  there  is  no  aluminum, 

1  Approximately  equivalent  to  2J  level  teaspoonfuls  of  alum  baking  powder.  Equlvalen  jto  about  0.22$ 
gram  (3.44  grains)  of  aluminum. 

•  Approximately  equivalent  to  4j  level  teaspoonfuls  of  alum  baking  powder. 

'Approximately  equivalent  to  6^,  level  teaspoonfuls  of  alum  baking  powder.  -These  amounts  of  alum 
are  equivalent  to  about  0.44  gram  (6.86  grains),  0.67  gram  (10.29  grains),  and  1.11  grams  (17.15  grains)of 
aluminum. 

1  Editorial  note:  Sodium  sulphate  or  Glauber's  salt  is  a  substance  derived  from  the  interaction  of  alum 
and  baking  soda  in  making  bread  with  alum  baking  powders,  and  is  of  itself  a  cathartic,  formerly  much  used 
medicinally.  Cream  of  tartar  baking  powder,  when  used  in  bread,  by  a  similar  interaction  produces  a 
cathartic  substance  known  as  sodium  tartrate.  Phosphate  baking  powders  when  used  in  making  bread 
produce  a  cathartic  substance  known  as  sodium  phosphate.  Cream  of  tartar  and  phosphate  baking  powderi 
produce  catharsis,  similar  to  that  produced  by  alum  baking  powders,  when  used  in  quantities. 

»  Approximately  equivalent  to  a  level  teaspoouful  of  alum  baking  powder. 

'Approximately  equivalent  to  3  level  teaspoonfuls  of  alum  baking  powder. 

'Approximately  equivalent  to  21  level  teaspoonfuls  of  alum  baking  powder. 

'Approximately  equivalent  to  10  level  teaspoonfuls  of  alum  baking  powder. 


Page  55 


BULLETIN   103,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


was  5.23  grams  l  (80.714  grains)  per  man  per  day.  Following  these 
experiments  four  men  took  1  gram  (15.433  grains)  of  aluminum  a  day 
each  for  several  days,2  and  then  their  blood  was  tested  to  detect  any 
aluminum  that  might  be  present  in  it.  No  aluminum  was  found  in 
the  blood.  As  a  further  indirect  test  to  determine  whether  aluminum 
was  resorbed,  one  man  took  for  five  days  enough  aluminum  hydroxide 
to  furnish  0.660  gram  (10.186  grains)  of  aluminum  a  day  and  another 
took  enough  to  give  0.540  gram -(8.334  grains)  a  day  for  five  days. 
The  men  were  fed  a  diet  of  low  and  known  phosphorus  content  and 
the  excrementa  analyzed  for  phosphorus,  in  order  to  detect,  if  pos- 
sible, signs  of  abstraction  of  this  element  from  the  tissues  by  resorbed 
aluminum.  This  test  failed  to  demonstrate  resorption  of  aluminum. 

CONCLUSIONS  OF  INDIVIDUAL  INVESTIGATORS. 

Dr.  Chittenden  concludes  from  his  experiments  that  small  quan- 
tities of  aluminum  compounds,  and  even  comparatively  large 
quantities,  when  taken  daily  with  the  food,  have  no  effect  upon  the 
general  health  and  nutrition  of  the  body.  "In  other  words,"  as  he 
sums  up  his  conclusions,  "aluminum  compounds  when  used  in  foods — 
as  in  bread — in  such  quantities  as  were  employed  in -our  experi- 
ments do  not  affect  injuriously  the  nutritive  value  of  such  foods  or 
render  them  injurious  to  health,  so  far  as  any  evidence  obtained  in 
our  experimental  work  indicates." 

Dr.  Long,  in  concluding  his  report,  calls  attention  to  the  fact  that 
alum  is  rather  generally  used  in  the  manufacture  of  cucumber  pickles. 
This  is  an  old  practice  which  had  its  origin  in  the  household  rather 
than  in  the  factory  and  is  still  common  hi  the  household.  The  harden- 
ing effect  of  the  alum  is  believed  to  help  in  keeping  the  pickles.  In 
the  factory  the  cucumbers  are  first  soaked  for  several  weeks  in  strong 
brine,  then  in  fresh  water  overnight,  this  process  being  sometimes 
repeated.  Then  the  cucumbers  are  put  into  an  alum  liquor  in  which 
the.  weight  of  alam  used  is  about  one-fourth  of  1  per  cent  of  the  weight 
of  the  cucumbers.  The  cucumbers  and  liquor  are  heated  up  to  120° 
or  140°  F.,  then  cooled  and  allowed  to  stand  for  from  6  to  24  hours. 
Then  comes  a  bath  in  fresh  water  and  afterwards  the  final  treat- 
ment with  vinegar.  The  vinegar  takes  "out  some  of  the  alum  from 
the  pickles,  so  that  usually  the  alum-left  in  them  amounts  to  less  than 
two-tenths  of  1  per  cent. 

Alum  is  also  used  in  the  preparation  of  maraschino  cherries,  and 
perhaps  some  other  fruits.  But  the  quantities  of  aluminum  that 
might  be  consumed  either  in  pickles  or  in  the  fruits  referred  to  are  so 
small,  compared  with  the  quantities  actually  consumed  in  baking 
powders,  that  thestudy,  of  alum  baking  powders  may  be  taken  to  cover 
the  entire  field. 

'About  one-fifth  ounce  of  Glauber'* salt.    {S«e -footnote,  p.  3.) 

*  This  corresponds  to  approximately  10  lew!  teaspooniuls  of  alum  baking  powder. 


Page  56 


ALUM  IN  FOODS. 


Alum,  as  such,  is  not  present  in  the  food  when  eaten.  In  the 
process  of  baking,  the  alum  and  soda  in  baking  powder  break  up  and 
recombine  into  several  compounds.  One  product  is  the  carbonic  acid 
gas,  which  does  the  work  of  leavening.  This  gas  passes  off,  leaving 
in  the  bread  an  aluminum  compound  and  a  compound  called  sodium 
sulphate.  Dr.  Long  concludes  that  the  cathartic  action  of  large  resi- 
dues from  the  alum  and  soda  combination — for  instance,  the  residue 

left  when  the  large  dose  of  alum,  4  grams  l  (61.732  grains),  was  used 

must  be  considered  objectionable  when  administered  daily.  But  this 
is  much  above  the  consumption  in  actual  practice,  and  amounts  of 
alum  not  above  2  grams  2  (30.866  grains)  a  day — a  liberal  allowance — 
do  not  appear  to  be  harmful  in  any  practical  sense.  Since  the  quan- 
tities of  aluminum  compounds  consumed  with  other  foods  are  insig- 
nificant compared  with  the  quantities  consumed  in  foods  prepared 
with  baking  powder,  the  findings  from  the  study  of  baking  powder 
residues  must  be  held  to  cover  all  cases.  Keeping  in  mind  that  the 
aluminum  compounds  actually  in  the  food  when  consumed  are  com- 
paratively inert,  Dr.  Long  declares  that  "it  can  not  be  said  that 
when  mixed  with  foods  in  the  small  quantities  actually  considered 
necessary,  they  add  a  poisonous  or  deleterious  substance,  or  injur- 
iously affect  the  quality  of  the  food  with  which  they  are  used." 

Dr.  Taylor's  conclusions  agree  in  effect  with  those  of  his  associates. 
He  says,  "We  have  had,  unquestionably,  evidences  of  the  catharsis 
caused  by  the  administration  of  large  doses  of  baking  powder.'* 
With  the  large  doses  used  in  his  experiments,  the  stools  are  increased 
in  weight  and  frequency,  the  movements  are  loose,  and  colic  is  apt 
to  attend  the  evacuations.  This  condition  is  the  result -of  sodium, 
sulphate,  which,  though  not  an  aluminum  compound,  is  a  residue  of 
the  alum  baking  powder.  But  with  very  largo  doses  of  aluminum 
compounds  occasional  dry  colic  may  also  be  noted. 

"I  personally,"  says  Dr.  Taylor,  "do  not  believe  that  it  would  be 
healthful  for  anyone,  in  camp  or  out  of  camp,  to  live  upon  a  diet  of 
baking  powder  biscuits.  I  do  not  believe  that  the  regular  ingestion 
of  sodium  sulphate  in  doses  of  from  3.5  to  5  grams  *  (54  to  77  grains) 
per  day,  with  the  normal  diet,  resulting  in  distinct  looseness  of  the 
bowels,  is  a  procedure  to  be  recommended.  Prolonged  administra- 
tion of  saline  cathartics  even  in  small  dose  tends  to  leave  behind  a 
condition  of  constipation;  and  it  is  certainly  the  experience  of  the 
medical  profession  that  the  practice  of  the  regular  administration  of 
saline  cathartics  is  not  to  be  recommended.  This  aspect  of  the  ques- 
tion is  of  course  not  peculiar  to  aluminum  baking  powder,  but  applies 
to  all  baking  powders,  since  to  a  greater  or  less  extent  a  saline  cathartic 
remains  as  the  residue  of  the  reactions  of  all  known  baking  powders, 

1  Approximately  equivalent  to  4J  level  teaspoonfuls  of  alum  baking  powder. 
»  Approximately  equivalent  to  2i  level  teaspoonfuls  of  alum  baking  powder. 
•One-eighth  to  one-sixth  ounce  of  Glauber's  salt. 


Page  57 


6  BULLETIN    103,    U     S.    DEPARTMENT  OF    AGRICULTURE. 


as  demonstrated  in  direct  tests  with  different  baking  powders  on 
human  subjects  *  There  is  no  evidence  in  our  results  to  indicate  that 
the  occasional  and  ordinary  use  of  bread,  biscuits,  or  cake  prepared 
with  aluminum  baking  powder  tends  to  injure  the  digestion.  The 
amount  of  saline  cathartic  that  would  be  ingested  under  conditions 
of  normal  diet  would  be  very  small  and  would  provoke  no  catharsis 
or  symptoms  of  any  kind." 

One  other  effect  of  the  administration  of  compounds  of  aluminum 
is  noted  by  Dr  Taylor,  namely,  a  distinct  decrease  of  phosphates  in 
the  urine  and  a  corresponding  increase  of  phosphates  in  the  stools. 
But  the  extent  of  this  change  is  too  slight  for  it  to  have  any  material 
meaning  of  effect. 

CONCLUSIONS  OP  THE  REFEREE  BOARD. 

With  the  results  of  these  independent  experiments  agreeing  so  well, 
the  Referee  Board  were  enabled  to  draw  up  a  unanimous  report,  signed 
by  all  the  members,  namely:  Ira  Remsen,  president  of  Johns  Hop- 
kins University,  chairman;  Russell  H.  Chittenden,  professor  of 
physiological  chemistry  in  Yale  University  and  director  of  the  Shef- 
field Scientific  School;  John  H.  Ldng,  professor  of  chemistry  in  the 
Northwestern  University  Medical  School;  Alonzo  E.  Taylor,  Benja- 
min Rush  professor  of  physiological  chemistry  hi  the  University  of 
Pennsylvania;  and  Theobald  Smith,  professor  of  comparative  path- 
ology in  Harvard  University. 

In  their  report  the  board  first  define  their  understanding  of  the 
terms  "small  quantity"  and  "large  quantity,"  as  appfied  to  alum 
baking  powders,  as  follows: 

By  the  term  *  small  quantity  "  we  understand  such  an  amount  as  may  be  ingested  in 
the  normal  ose  of  biscuits,  pastry,  or  other  articles  leavened  with  baking  powder,  as 
these  foods  are  practically  used  in  tha  ordinary  American  family.  This  amount  will 
not  average  more  than  25  to  75.  milligrams  3  (0.39  to  1.16  grains)  of  aluminum  daily 
for  the  days  of  consumption  of  such  articles. 

1  "We  must  not,  however,  be  oblivious  to  the  fact,"  says  Dr.  Taylor, 
who  conducted  part  of  these  investigations,  "that  a  saline  cathartic 
residue  results  from  the  reaction  of  every  form  of  known  baking  pow- 
der now  commonly  employed.  The  use  of  cream  of  tartar  or  tartaric 
acid  baking  powder  leaves  in  the  alimentary  tract  a  residue  of  tartrates 
which  exhibit  the  action  of  a  saline  cathartic  and  of  diuresis  [excessive 
excretion  of  urine]  as  well.  The  so-called  phosphate  baking  powder 
leaves  as  a  residue  of  reaction  sodium  pnospnate,  again  a  saline 
cathartic.  And  aluminum  baking  powder  leaves  as  a  residue  of 
reaction  sodium  sulphate,  a  saline  cathartic.  Apparently  therefore, 
at  present  at  least,  the  use  of  baking  powder  is  associated  with  the 
introduction  into  the  alimentary'  tract  of  a  certain  amount  of  saline 
cathartic,  the  salt  differing  with  the  use  of  the  particular  type  of 
baking  powder." 

»  This  is  approximately  equivalent  to  one-quarter  to  three^uarters  of  a  level  teaspopnful  of  alum  bakin* 
«owder. 


Page  58 


ALUM    IN    FOODS. 


B  /  the  term  "large  quantity  "  we  understand  such  an  amount  of  aluminum  as  would 
be  ingested  only  under  very  unusual  conditions,  as  :'or  example,  where  the  flour  con- 
sumption is  mainly  in  the  form  of  biscuits  or  other  articles  'ravened  with  aluminum 
baking  powders.  This  amount  may  reach  150  to  200  milligrams  '  (2  31  to  3  09  grains) 
of  aluminum  per  day  A  person  subsisting  mamly  on  baking-powder  biscuits,  as  may 
happen  in  camp  life,  might  ingest  an  amount  in  excess  of  200  milligrams  per  day. 
With  this  possibility  in  mind,  we  have  also  studied  the  effects  of  amounts  up  to  and 
exceeding  1,000  milligrams  3  (15  4  grains}  of  aluminum  per  day 

With  this  understanding  of  the  terms,  the  board  give  the  following 
answers  to  the  questions  submitted  to  them 

Aluminum  compounds  when  used  in  the  form  of  baking  powders  in  foods  have  not 
been  found  to  affect  injuriously  the  nutritive  value  of  such  foods 

Aluminum  compounds  when  added  to  foods  in  the  form  of  bakine;  powders,  in  small 
quantities,  have  not  been  found  to  contribute  any  poisonous  or  other  deleterious  effect 
w.hich  may  render  the  said  food  injurious  to  health.  The  same  holds  true  for  the  amount 
of  aluminum  which  may  be  included  in  the  ordinary  consumption  of  aluminum 
baking  powders  furnishing  up  to  150  milligrams  (2  31  grains)  of  aluminum  daily. 

Aluminum  compounds  when  added  to  foods,  in  the  form  of  baki.ng  powders,  in  large 
quantities,  up  to  200  milligrams  (3  09  grains)  or  more  per  day,  may  provoke  mild 
catharsis 

Very  large  quantities  of  aluminum  taker  with  foods  in  the  form  of  baking  powders 
usually  provoke  catharsis  This  action  of  aluminum  baking  powders  is  due  to  the 
sodium-sulphate  which  results  from  the  reaction 

The  aluminum  itself  has  not  been  found  to  exert  any  deleterious  action  injurious 
to  health,  beyond  the  production  of  occasional  colic  when  very  large  amounts  have 
been  ingested. 

When  aluminum  compounds  are  mixed  or  packed  with  a  food,  the  quality  or  strength 
of  said  food  has  not  been  found  to  be  thereby  reduced,  lowered,  or  injuriously  affected. 

In  short,  the  board  conclude  that  alum  baking  powders  are  no 
more  harmful  than  any  other  baking  powders,  but  that  it  is  wise 
to  be  moderate  in  the  use  of  foods  that  are  leavened  with  baking 
powder.3 

'  This  is  approximately  equivalent  to  1J  to  2  level  teaspoonfuls  alum  baking  powder. 
'Approximately  equivalent  to  10  level  teaspoonfuls  alum  baking  powder. 
'See  footnotes,  pages  3  and  6. 


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